Data from: Cortico-striatal action control inherent of opponent cognitive-motivational styles
Data files
Feb 20, 2025 version files 128.74 KB
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data_Avila_and_Sarter_2025.zip
16.80 KB
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data_Avila_and_Sarter.xlsx
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README.md
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Abstract
Turning on cue or stopping at a red light requires attending to such cues to select action sequences, or suppress action, in accordance with learned cue-associated action rules. Cortico-striatal projections are an essential part of the brain’s attention-motor interface. Glutamate-sensing microelectrode arrays were used to measure glutamate transients in the dorsomedial striatum (DMS) of male and female rats walking a treadmill and executing cued turns and stops. Prelimbic-DMS projections were chemogenetically inhibited to determine their behavioral necessity and the cortico-striatal origin of cue-evoked glutamate transients. Furthermore, we investigated rats exhibiting preferably goal-directed (goal trackers, GTs) versus cue-driven attention (sign trackers, STs), to determine the impact of such cognitive-motivational biases on cortico-striatal control. GTs executed more cued turns and initiated such turns more slowly than STs. During turns, but not missed turns or cued stops, cue-evoked glutamate concentrations were higher in GTs than in STs. In STs, turn cue-locked glutamate concentrations frequently peaked twice or three times, contrasting with predominately single peaks in GTs. In GTs, but not STs, inhibition of prelimbic-DMS projections attenuated turn rates and turn cue-evoked glutamate concentrations and increased the number of turn cue-locked glutamate peaks. These findings indicate that turn cue-evoked glutamate release in GTs is tightly controlled by cortico-striatal neuronal activity. In contrast, in STs, glutamate release from DMS glutamatergic terminals may be regulated by other striatal circuitry, preferably mediating cued suppression of action and reward tracking. As cortico-striatal dysfunction has been hypothesized to contribute to a wide range of disorders, including complex movement control deficits in Parkinson’s disease and compulsive drug taking, the demonstration of phenotypic contrasts in cortico-striatal control implies the presence of individual vulnerabilities for such disorders.
https://doi.org/10.7554/eLife.100988.2
Dataset Overview:
This dataset contains the data used to generate figures in Avila and Sarter (2024), testing the hypothesis that variations in the individual capacity for cortico-striatal processing of movement cues contribute to the expression of opponent cognitive-motivational styles: goal-directed (goal-trackers, GTs) versus stimulus-driven (sign-trackers, STs). Four cohorts of female and male rats were screened over 19 months and classified as GTs, STs, or intermediates (not assessed in these experiments). A subset of GTs and STs received intracranial infusions of a Cre-dependent DREADD into the frontal cortex and a retrogradely transported Cre-expressing plasmid into the dorsomedial striatum (DMS) to inhibit fronto-cortical projections to the DMS. These rats were then trained and tested on a treadmill task requiring them to execute cued turns and stops, both with and without cortico-striatal inhibition. The behavioral measurements include the PCA index scores across five screening days, cued movement metrics: number of cued turns (turns/turn trials), missed turns, cued stops (stops/stop trials), false turns, cued turn timing metrics: individual turn onset and completion times, extracted from offline scoring of CTTT session videos. Additionally, CTTT behavioral metrics were averaged across test sessions baseline CTTT performance between GTs and STs, as well as performance with or without cortico-striatal inhibition (CNO or vehicle injections). This dataset also contains electrochemical data. Glutamate-sensing microelectrode arrays were implanted in a subset of rats to measure glutamate transient levels (denoted in µM). Data were collected at a fixed potential of 0.7 V using a FAST-16 potentiostat at 5 Hz and processed offline with MATLAB scripts. Calibration curves were used to quantify glutamate concentrations, and data were analyzed across baseline, cue, and reward periods of the CTTT. Electrochemical data include representative traces of glutamate and GT signals, trace characteristics, maximum amplitudes (peaks), and number of peaks. Data analyses included linear mixed-effects models and repeated measures ANOVA, with Bonferroni corrections for post hoc comparisons. Therefore, estimated marginal means (EMMs), means, and confidence intervals (upper and lower limits) were provided for significant figures. Lastly, semi-quantitative estimates of transfection efficacy in the prelimbic cortices and the proportion of double-labeled neurons were correlated with the difference in cued turns between CNO and saline. conditions. Analysis of behavioral metrics showed significant differences between GTs and STs in cued movement execution. Electrochemical recordings revealed that glutamate transient levels in the dorsomedial striatum varied by phenotype and experimental condition, supporting the hypothesis that cortico-striatal activity differentially contributes to movement control in these cognitive-motivational styles. Additionally, analysis of transfection efficacy and anatomical spread suggested that individual variability in neural modulation contributed to differences in movement behavior under DREADD inhibition.
Description of the data and file structure
This repository contains the processed data used in Avila and Sarter (2024). Raw data were processed using MATLAB for electrochemical analyses, while statistical analyses were conducted primarily in SPSS and GraphPad Prism. Users are provided with the processed datasets required for replication, so access to MATLAB is not necessary. File names correspond to the plots for major figures in the manuscript, categorized below based on behavioral metrics, electrochemical measurements, and experimental conditions, with summary statistics provided for key figures.
Files
Baseline Data
PCA_index_across_days.csv
This file contains the Pavlovian Conditioned Approach (PCA) index scores of rats across five screening days. Rats are categorized as goal-trackers (GT) or sign-trackers (ST). The final phenotype classification is determined based on the average PCA scores from the 4th and 5th test sessions.
Number of variables: 3
Number of header rows: 1
Number of rows: 255
Variable list:
- Phenotype: (alphanumeric) Classification assigned after PCA screening.
- Day: (numeric) PCA screening days 1-5.
- PCA Index (numeric) PCA index scores.
Data type: alphanumeric, numeric
PCA_phenotype_by_sex.csv
This file provides counts of female and male rats categorized by phenotype. It also includes the total number of rats screened and the proportion of each phenotype relative to the total.
Number of variables: 7
Number of header rows: 1
Number of rows: 4
Variable list:
- F: (character) female rats.
- M: (character) male rats.
- GT: (character) GT rats.
- IN: (character) intermediate rats [not included in these experiments].
- ST: (character) ST rats.
- Sum/total: (alphanumeric) Total number of rats across categories.
- phenotype/total: (alphanumeric) The proportion relative to the total number of rats screened for each phenotype.
Data type: alphanumeric, character
PCA_phenotype_by_vendor.csv
This file provides counts of rats by two vendors (Inotiv and Taconic), broken down by sex and phenotype. It also includes the total number of rats screened by the vendor and the proportion of each phenotype within each vendor.
Number of variables: 9
Number of header rows: 1
Number of rows: 4
Variable list:
- Inotiv F: (alphanumeric) Counts of female rats from Inotiv.
- Taconic F: (alphanumeric) Counts of female rats from Taconic.
- Inotiv M: (alphanumeric) Counts of male rats from Inotiv.
- Taconic M: (alphanumeric) Counts of male rats from Taconic.
- Inotiv/Taconic total: (alphanumeric) Counts of all rats from Inotiv or Taconic.
- GT: (character) GT rats.
- IN: (character) intermediate rats [not included in these experiments].
- ST: (character) ST rats.
- Sum: (alphanumeric) Total number of rats across categories.
- Inotiv/Tacnoic phenotype/total: (alphanumeric) The proportion relative to the total number of rats screened for each phenotype by vendor.
Data type: alphanumeric, character
Days_to_criteria_by_phenotype.csv
This file provides the number of training sessions (measured in days) required for each rat to reach behavioral criterion performance on the cue-triggered turning task. The criterion is defined as achieving 70% correct responses to both cues for two consecutive sessions. The data is grouped by phenotype (Goal-trackers vs. Sign-trackers).
Number of variables: 2
Number of header rows: 1
Number of rows: 51
Variable list:
- Phenotype: (alphanumeric) Classification assigned after PCA screening.
- Days to criteria: (numeric) The number of training sessions (days) each rat needed to reach the behavioral criterion
Data type: alphanumeric, numeric
Baseline_performance.csv
This file provides the baseline cued turning performance of Goal-tracker (GT) and Sign-tracker (ST) rats (turn/turn trials) across four test sessions, conducted after the rats reached criterion performance and before any experimental manipulations.
Number of variables: 2
Number of header rows: 1
Number of rows: 51
Variable list:
- Phenotype: (alphanumeric) Classification assigned after PCA screening.
- turns/turn trials: (numeric) The proportion of cued turns over the total number of turn cue trials averaged across 4 test sessions.
Data type: alphanumeric, numeric
Baseline_performance_across_days.csv
This file provides the baseline CTTT (Cue-triggered Turning Task) performance of Goal-tracker (GT) and Sign-tracker (ST) rats (turn/turn trials and stop/stop trials) across four test sessions, conducted after the rats reached criterion performance and before any experimental manipulations.
Number of variables: 4
Number of header rows: 1
Number of rows: 204
Variable list:
- Phenotype: (alphanumeric) Classification assigned after PCA screening.
- Day: (numeric) 4 baseline test sessions
- turns/turn trials: (numeric) The proportion of cued turns over the total number of turn cue trials averaged across 4 test sessions.
- stops/stop trials: (numeric) The proportion of cued stops over the total number of stop cue trials across 4 test sessions.
Data type: alphanumeric, numeric
Baseline_time_to_turn.csv
This file provides the baseline individual turn onset and completion times, relative to cue onset, of Goal-tracker (GT) and Sign-tracker (ST) rats averaged across 4 test sessions.
Number of variables: 3
Number of header rows: 1
Number of rows: 51
Variable list:
- Phenotype: (alphanumeric) Classification assigned after PCA screening.
- initiation: (numeric) Individual time of turn onset relative to cue onset (measured in seconds).
- completion: (numeric) Individual time to complete turn relative to cue onset (measured in seconds).
Data type: alphanumeric, numeric
Electrochemical Data-
Representative_Glu_traces_GT.csv
This file provides 5 representative amperometry traces from Goal-tracker (GT) rats implanted with glutamate-sensing microelectrode arrays into the dorsomedial striatum. The traces were recorded during cued turns.
Number of variables: 2
Number of header rows: 1
Number of rows: 41
Variable list:
- time: (numeric) Time in seconds, from 2 seconds before cue onset (0s) up to 6 seconds post-cue.
- Glutamate concentrations (µM): (numeric) Individual traces of glutamate concentration levels in µM for each of the 5 representative traces
Data type: numeric
Representative_Glu_traces_ST.csv
This file provides 5 representative amperometry traces from Sign-tracker (ST) rats implanted with glutamate-sensing microelectrode arrays into the dorsomedial striatum. The traces were recorded during cued turns.
Number of variables: 2
Number of header rows: 1
Number of rows: 41
Variable list:
- time: (numeric) Time in seconds, from 2 seconds before cue onset (0s) up to 6 seconds post-cue.
- Glutamate concentrations (µM): (numeric) Individual traces of glutamate concentration levels in µM for each of the 5 representative traces
Data type: numeric
Max_amp_cued_turns.csv
This file provides maximum glutamate peak concentrations recorded during the turn cue period in Goal-tracker (GT) and Sign-tracker (ST) rats. The concentrations were extracted during cued turns.
Number of variables: 2
Number of header rows: 1
Number of rows: 351
Variable list:
- Phenotype: (alphanumeric) Classification assigned after PCA screening.
- µM: (numeric) Maximum glutamate amplitude in µM during cued turns
Data type: alphanumeric, numeric
Peaks_cued_turns_traces.csv
This file provides counts for traces with 1, 2, or 3 peaks (maximum glutamate concentrations) during the turn cue period in Goal-tracker (GT) and Sign-tracker (ST) rats. The number of peaks was extracted during cued turns.
Number of variables: 5
Number of header rows: 1
Number of rows: 2
Variable list:
- GT: (character) GT rats.
- ST: (character) ST rats.
- 1 peak: (alphanumeric) The counts for traces with 1 peak in GT and ST rats
- 2 peaks: (alphanumeric)The counts for traces with 2 peaks in GT and ST rats
- 3 peaks: (alphanumeric)The counts for traces with 3 peaks in GT and ST rats
Data type: character, alphanumeric
Max_amp_misses.csv
This file provides maximum glutamate peak concentrations recorded during the turn cue period in Goal-tracker (GT) and Sign-tracker (ST) rats. The concentrations were extracted during missed turn cue trials (misses).
Number of variables: 2
Number of header rows: 1
Number of rows: 195
Variable list:
- Phenotype: (alphanumeric) Classification assigned after PCA screening.
- µM: (numeric) Maximum glutamate amplitude in µM during misses
Data type: alphanumeric, numeric
Max_amp_cued_stops.csv
This file provides maximum glutamate peak concentrations recorded during the stop cue period in Goal-tracker (GT) and Sign-tracker (ST) rats. The concentrations were extracted during cued stops.
Number of variables: 2
Number of header rows: 1
Number of rows: 220
Variable list:
- Phenotype: (alphanumeric) Classification assigned after PCA screening.
- µM: (numeric) Maximum glutamate amplitude in µM during cued stops
Data type: alphanumeric, numeric
Max_amp_reward_delivery.csv
This file provides maximum glutamate peak concentrations recorded during reward delivery in Goal-tracker (GT) and Sign-tracker (ST) rats. The concentrations were extracted during the reward delivery preceding a cued turn or stop.
Number of variables: 2
Number of header rows: 1
Number of rows: 195
Variable list:
- Phenotype: (alphanumeric) Classification assigned after PCA screening.
- µM: (numeric) Maximum glutamate amplitude in µM during reward delivery
Data type: alphanumeric, numeric
Relative_probabilities_cued_turns.csv
This files provides the relative probability of executing a cued turn in GT rats depending on the characteristics of peak glutamate concentrations.
Number of variables: 5
Number of header rows: 1
Number of rows: 13
Variable list:
- GLU maximum peak (µM): (numeric) Classification assigned after PCA screening.
- GLU peaks > or equal x: (numeric) Classification assigned after PCA screening.
- 1st peak only, GLU peaks > or equal x: (numeric) Classification assigned after PCA screening.
- 1 peak only, GLU peaks > or equal x: (numeric) Classification assigned after PCA screening.
- 2 and 3 peaks: (numeric) Classification assigned after PCA screening.
Data type: numeric
Representative_GT_traces_Fig6.csv
This file provides 4 representative amperometry traces from Goal-tracker (GT) rats implanted with glutamate-sensing microelectrode arrays into the dorsomedial striatum. The traces were recorded during cued turns and illustrate the different characteristics (peak amplitude, single versus multiple peaks) across the traces.
Number of variables: 2
Number of header rows: 1
Number of rows: 31
Variable list:
- time: (numeric) Time in seconds, from 2 seconds before cue onset (0s) up to 4 seconds post-cue.
- Glutamate concentrations (µM): (numeric) Individual traces of glutamate concentration levels in µM for each of the 4 representative traces
Data type: numeric
Experimental Conditions-
CTTT_performance_by_injection.csv
This file provides the CTTT (Cue-triggered Turning Task) performance of Goal-tracker (GT) and Sign-tracker (ST) rats (turn/turn trials and stop/stop trials), averaged across test sessions after the rats received either a vehicle (saline) or CNO injection.
Number of variables: 4
Number of header rows: 1
Number of rows: 44
Variable list:
- Phenotype: (alphanumeric) Classification assigned after PCA screening.
- Injection: (alphanumeric) Injection received, saline or CNO.
- turns/turn trials: (numeric) The proportion of cued turns over the total number of turn cue trials averaged across 4 test sessions.
- stops/stop trials: (numeric) The proportion of cued stops over the total number of stop cue trials average across 4 test sessions.
Data type: alphanumeric, numeric
Max_amp_cued_turns_by_injection.csv
This file provides the maximum glutamate peak concentrations recorded during the turn cue period in Goal-tracker (GT) and Sign-tracker (ST) rats, following either a vehicle (saline) or CNO injection. The concentrations were extracted during cued turns.
Number of variables: 3
Number of header rows: 1
Number of rows: 206
Variable list:
- Phenotype: (alphanumeric) Classification assigned after PCA screening.
- Injection: (alphanumeric) Injection received, saline or CNO.
- µM: (numeric) Maximum glutamate amplitude in µM during cued turns
Data type: alphanumeric, numeric
Peaks_cued_turns_by_injection.csv
This file provides counts for traces with 1, 2, or 3 peaks (maximum glutamate concentrations) during the turn cue period in Goal-tracker (GT) and Sign-tracker (ST) rats, following either a vehicle (saline) or CNO injection. The number of peaks was extracted during cued turns. Column A serves as a label for the number of peaks, while Columns B-E contain the corresponding counts for each condition.
Number of variables: 4
Number of header rows: 1
Number of rows: 3
Variable list:
- GTs-SAL: (alphanumeric) Count of traces with 1, 2, or 3 peaks in GT rats after a vehicle (saline) injection
- GTs-CNO: (alphanumeric) Count of traces with 1, 2, or 3 peaks in GT rats after a CNO injection
- STs-SAL: (alphanumeric) Count of traces with 1, 2, or 3 peaks in ST rats after a vehicle (saline) injection
- STs-CNO: (alphanumeric) Count of traces with 1, 2, or 3 peaks in ST rats after a CNO injection
Data type: alphanumeric
Time_to_ini_turn_by_injection.csv
This file provides individual turn onsets of Goal-tracker (GT) and Sign-tracker (ST) rats averaged across test sessions, following either a vehicle (saline) or CNO injection.
Number of variables: 3
Number of header rows: 1
Number of rows: 185
Variable list:
- Phenotype: (alphanumeric) Classification assigned after PCA screening.
- Injection: (alphanumeric) Injection received, saline or CNO.
- initiation: (numeric) Individual time of turn onset relative to cue onset (measured in seconds).
Data type: alphanumeric, numeric
Max_amp_misses_by_injection.csv
This file provides the maximum glutamate peak concentrations recorded during the turn cue period in Goal-tracker (GT) and Sign-tracker (ST) rats, following either a vehicle (saline) or CNO injection. The concentrations were extracted during missed turn cue trials (misses).
Number of variables: 3
Number of header rows: 1
Number of rows: 138
Variable list:
- Phenotype: (alphanumeric) Classification assigned after PCA screening.
- Injection: (alphanumeric) Injection received, saline or CNO.
- µM: (numeric) Maximum glutamate amplitude in µM during misses
Data type: alphanumeric, numeric
Max_amp_reward_delivery_by_injection.csv
This file provides the maximum glutamate peak concentrations recorded during the reward delivery in Goal-tracker (GT) and Sign-tracker (ST) rats, following either a vehicle (saline) or CNO injection. The concentrations were extracted during the reward delivery preceding a cued turn or stop.
Number of variables: 3
Number of header rows: 1
Number of rows: 344
Variable list:
- Phenotype: (alphanumeric) Classification assigned after PCA screening.
- Injection: (alphanumeric) Injection received, saline or CNO.
- µM: (numeric) Maximum glutamate amplitude in µM during reward delivery.
Data type: alphanumeric, numeric
CTTT_performance_by_transfection.csv – Behavioral performance as a function of transfection efficacy.
This file contains semi-quantitative estimates of transfection efficacy for eGFP in the DMS and mCherry in the prelimbic cortex, with higher scores indicating more precise labeling in the target region of the prelimbic cortex. It also includes the proportion of double-labeled neurons and the difference in the proportion of turns/turn trials between saline and CNO injections (denoted as turns/turn trials (saline-CNO)) in Goal-trackers (GT) and Sign-trackers (ST) rats. The estimates of transfection efficacy and the proportion of double-labeled neurons were tested for correlations against the turns/turn trials (saline-CNO).
Number of variables: 4
Number of header rows: 1
Number of rows: 21
Variable list:
- Phenotype: (alphanumeric) Classification assigned after PCA screening.
- PL score : (numeric): Maximum glutamate amplitude in µM during reward delivery.
- proportion of PL: (numeric): The proportion of double-labeled neurons in the prelimbic cortex
- turns/turn trials (saline-CNO): (numeric) The difference in the proportion of turns/turn trials between saline and CNO injections in GT and ST rats
Data type: alphanumeric, numeric
Statistical Summaries-
Figure3_summary_stats.csv
This file contains summary statistics, including the means and confidence intervals, for Figure 3 comparing CTTT behavioral measurements in Goal-trackers (GT) and Sign-trackers (ST).
Number of numeric variables: 3
Number of categorical headers: 5
Number of header rows: 2
Number of rows: 3
Variable list:
- Mean: (numeric) Mean for behavioral measurement
- Upper Limit: (numeric) Upper limit of confidence interval for behavioral measurement
- Lower Limit: (numeric) Lower limit of confidence interval for behavioral measurement
Behavioral Categories (alphanumeric, headers)
Days to criteria: Number of days required to reach the learning criteria.
Turns/turn trials: Proportion of turns per turn trials.
Stops/stop trials: Proportion of stops per stop trials.
Initiation: Time from cue onset to the initiation of a turn (seconds).
Completion: Time from cue onset to turn completion (seconds).
Each behavioral category contains GT (Goal-trackers) and ST (Sign-trackers) as subcategories.
Data type: alphanumeric, numeric
Figure5_summary_stats.csv
This file contains summary statistics, including estimated marginal means (EMMs) and confidence intervals, for Figure 5 comparing glutamate concentrations time-locked to turn and stop cues, as well as reward delivery, in Goal-Tracker (GT) and Sign-Tracker (ST) rats.
Number of numeric variables: 3
Number of header rows: 2
Number of rows: 3
Variable list:
- Estimated marginal means: (numeric) Estimated marginal means for behavioral measurement
- Upper Limit: (numeric) Upper limit of confidence interval for behavioral measurement
- Lower Limit: (numeric) Lower limit of confidence interval for behavioral measurement
Behavioral Categories (alphanumeric, headers)
Cued turns: Glutamate amplitude during the turn cue period in cued turns (GT, ST)
Misses: Glutamate amplitude during the turn cue period in missed trials (misses) (GT, ST)
Cued stops: Glutamate amplitude during the stop cue period in cued stops (GT, ST)
Reward delivery: Glutamate amplitude during reward delivery (GT, ST)
Data type: alphanumeric, numeric
Figure7_summary_stats.csv
This file contains estimated means, marginal means (EMMs) and confidence intervals for three separate plots from Figure 7, analyzing CTTT behavioral metrics and glutamate transient activity in Goal-Tracker (GT) and Sign-Tracker (ST) rats following either a vehicle (saline) or CNO injection.
Number of numeric variables: 4
Number of categorical headers: 6
Number of header rows: 6
Number of rows: 9
Variable list:
- Mean: (numeric) Mean for behavioral measurement
- Estimated marginal means: (numeric) Estimated marginal means for behavioral measurement
- Upper Limit: (numeric) Upper limit of confidence interval for behavioral measurement
- Lower Limit: (numeric) Lower limit of confidence interval for behavioral measurement
Behavioral Categories (alphanumeric, headers)
Turns/turn trials: Proportion of turns/turn trials in GT Saline, GT CNO, ST Saline, and ST CNO
Stops/stop trials: Proportion of stops/stop trials in GT Saline, GT CNO, ST Saline, and ST CNO
Cued turns: Glutamate amplitude during the turn cue period in cued turns in GT Saline, GT CNO, ST Saline, and ST CNO.
Misses: Glutamate amplitude during the turn cue period in missed trials (misses) in GT Saline, GT CNO, ST Saline, and ST CNO.
Cued stops: Glutamate amplitude during the stop cue period in cued stops in GT Saline, GT CNO, ST Saline, and ST CNO.
Reward delivery: Glutamate amplitude during reward delivery in GT Saline, GT CNO, ST Saline, and ST CNO.
Initiation: Turn onset times in GT Saline, GT CNO, ST Saline, and ST CNO.
Each behavioral category contains GT (Goal-trackers)_saline, GT_CNO, ST (Sign-trackers)_saline, and ST_CNO as subcategories.
Data type: alphanumeric, numeric
data_Avila and Sarter.xlsx
This excel workbook contains all data sheets listed above combined and separated by tab.
Sharing/Access information
Links to publicly accessible locations of the data:
[Link will be added after Dryad upload]
Data was derived from the following sources:
This dataset was generated from original experiments conducted by Dr. Cassandra Avila under the supervision of Dr. Martin Sarter in the Psychology Department at the University of Michigan-Ann Arbor.
Software
SPSS 28.0
GraphPad Prism 10.1.2
MATLAB R2023a
PeakDet function
Subjects and Behavioral Training: Male and female rats were trained on the Cue-Triggered Turning Task (CTTT) to assess cued turn and stop performance. Rats were classified as goal trackers (GTs) or sign trackers (STs) via Pavlovian Conditioned Approach (PCA) screening.The number of cued turns, missed turns, cued stops, and false turns were extracted from offline scoring of CTTT session videos. For the analysis of baseline CTTT performance, and because rats generated a variable number of cued turns during the 4 sessions used for this analysis, individual turn onset and completion times were averaged across the test sessions.
Chemogenetic Manipulation: Rats underwent intracranial infusions of Cre-dependent Designer Receptor Exclusively Activated by Designer Drug (DREADD) and retrogradely transported Cre-expressing plasmids to inhibit fronto-cortical projections to the dorsomedial striatum (DMS) before CTTT acquisition. A second surgery was performed for the implantation of microelectrode arrays (MEAs) into the dorsomedial striatum following CTTT acquisition.
CNO Administration: Clozapine N-oxide (CNO, 5.0 mg/kg) or vehicle was administered intraperitoneally 50 minutes prior to CTTT testing on alternate days. CNO effects were assessed in rats with either the DREADD or control vector, and for electrochemical data, CNO was given just before baseline recordings. Statistical analyses were performed to examine the effects of CNO or vehicle treatment on behavior, using repeated measures ANOVA and Tukey’s post hoc tests.
Electrochemical Data Collection: Glutamate concentrations in the dorsomedial striatum were recorded using glutamate-sensitive microelectrode arrays (MEAs). Data were collected at a fixed potential of 0.7 V using a FAST-16 potentiostat at 5 Hz and processed offline with MATLAB scripts. Calibration curves were used to quantify glutamate concentrations, and data were analyzed during baseline, cue, and reward periods of the CTTT. Statistical analyses included linear mixed-effects models and repeated measures ANOVA, with Bonferroni corrections for post hoc comparisons.
Histology and Verification: Following the study, rats were euthanized, and brains were processed for histological verification of viral infusion and electrode placement. Fluorescent microscopy and confocal imaging were used to assess the distribution of transfected neurons. Transfection efficacy was semi-quantified based on GFP and mCherry labeling, and cell counts were performed to determine the proportion of double-labeled neurons.