Journal: Cerebral Cortex (New York, NY)

Article Title: Stress Degrades Prefrontal Cortex Neuronal Coding of Goal-Directed Behavior

doi: 10.1093/cercor/bhw140

Figure Lengend Snippet: Multiple task-related spiking activity profiles of single dmPFC neurons during T-maze task trials. (a) For each trial, the subject progresses through a sequence of events including a delay period in the start box (ai), hand-fed reward for a correct response (aii), and removal of the animal from the maze (aiii) to begin another trial. (b) Video tracking and infrared beams are used to timestamp maze events (trace = 7 trials). (c) Coronal section demonstrating recording site in dmPFC. Detail of electrode tip placement in adjacent section (400× inset). Arrow indicates recording surface location in Layer V. Scale bar, 150 µm; ACg, anterior cingulate; PL, prelimbic cortex; IL, infralimbic cortex. (d) Action potentials were classified as WS type (di; output neuron) or NS-type (dii; interneuron). (e) Stress impairs correct performance of this task (n = 13 sessions; mean ± SEM; **P < 0.001). Peri-event spike rasters (top) and time histograms (PETH; bottom) of a delay neuron (f), reward neuron (g), or pickup neuron (h) during left-correct (left) or right-correct (right) trials (Inset = spike waveforms). Shape of fiduciaries indicates the beginning of each event and used throughout all figures.

Article Snippet: Statistical Analyses Peri-event time histogram (PETH) analysis was used to determine the mean spiking probability on a trial-by-trial basis during each task event interval (250 ms bin, Devilbiss et al. 2012 ).

Techniques: Activity Assay, Sequencing

Journal: Cerebral Cortex (New York, NY)

Article Title: Stress Degrades Prefrontal Cortex Neuronal Coding of Goal-Directed Behavior

doi: 10.1093/cercor/bhw140

Figure Lengend Snippet: Stress suppresses task-related spiking activity of strongly tuned WS-neurons. (a) Stress suppresses delay-related activity of strongly tuned dmPFC neurons (n = 57). ai, Spike rasters and PETHs of a delay neuron during correct or error trials from baseline and stress conditions. X-axes = time (seconds) before and after start of delay, Y-axes = spike probability, gray bar = delay interval (Inset = spike waveforms). (aii) Mean delay-related activity for correct or error trials was suppressed by stress. Chance level of performance = 50% correct. (aiii) Stress reduced the size of the population of delay-tuned neurons. (b) Stress suppresses reward responses (n = 55). (bi) Rasters and PETHs of a reward-tuned neuron demonstrating a robust stress-related suppression of reward-related signaling. PETH X-axes are aligned to delivery of reward. (bii) Stress suppressed mean reward-related responses. (biii) Stress suppressed the population size of reward-tuned neurons. NA = reward was not given on error trials. (c) Stress suppressed pickup-related spiking (n = 46). Rasters and PETHs of a pickup-tuned neuron are aligned to initial touch by the experimenter. The absence of initial response to touching animal (ci 1st panel) indicates that pickup response is not sensory mediated. Under Baseline conditions, this neuron exhibited a greater pickup response after error trials, indicative of an error-related signal. (cii) Stress suppressed mean pickup-related responses for both correct and error trials. Error trials demonstrated the highest sensitivity to stress. (ciii) The population size of pickup-tuned neurons was reduced during stress. Left and right trial activity was combined for population analyses. Probabilities >1 indicate that on average the interval contained >1 spike/bin/trial. Bar graphs = mean ± SEM. *P< 0.05; **P< 0.001.

Article Snippet: Statistical Analyses Peri-event time histogram (PETH) analysis was used to determine the mean spiking probability on a trial-by-trial basis during each task event interval (250 ms bin, Devilbiss et al. 2012 ).

Techniques: Activity Assay

Journal: Cerebral Cortex (New York, NY)

Article Title: Stress Degrades Prefrontal Cortex Neuronal Coding of Goal-Directed Behavior

doi: 10.1093/cercor/bhw140

Figure Lengend Snippet: Effects of stress on task-related spiking activity of dmPFC putative interneurons. (a) Stress significantly suppressed spiking activity of strongly tuned delay-related NS neurons (n = 10). Exemplar delay neuron rasters and PETHs from correct or error trials during baseline and stress conditions. X-axes = time (s) before and after start of delay, Y-axes = spike probability, gray bar = delay interval (Inset = spike waveforms). (aii) Average delay-related activity during correct and error trials was suppressed by stress. (aiii) Stress completely eliminated the population of strongly delay-tuned NS neurons. (b) Reward-related responses were not effected by stress (n = 12). (bi) Reward-tuned neuron rasters and PETHs demonstrating a moderate suppression of reward-related signaling. PETH X-axes are aligned to delivery of reward. (bii) The average of reward-related responses was not affected by stress. (biii) Stress did not affect the population size of reward-tuned NS neurons. NA = reward was not given on error trials. (c) Stress did not significantly suppress pickup-related spiking (n = 14). (ci) Rasters and PETHs of a pickup-tuned neuron are aligned to initial touch by the experimenter. During baseline conditions, this pickup neuron exhibited a greater pickup response after correct trials. (cii) Stress did not significantly suppress the mean pickup-related responses for both correct and error trials. (ciii) The population size of pickup-tuned neurons was slightly reduced during stress. Bar graphs = mean ± SEM.

Article Snippet: Statistical Analyses Peri-event time histogram (PETH) analysis was used to determine the mean spiking probability on a trial-by-trial basis during each task event interval (250 ms bin, Devilbiss et al. 2012 ).

Techniques: Activity Assay

Journal: Cerebral Cortex (New York, NY)

Article Title: Stress Degrades Prefrontal Cortex Neuronal Coding of Goal-Directed Behavior

doi: 10.1093/cercor/bhw140

Figure Lengend Snippet: Stress suppresses multiplexed task-related spiking activity. (a) Multiplexed responses of delay-tuned neurons. (ai) Spiking rasters and PETHs of a delay-tuned neuron also responsive to pickup (PETH aligned to pickup). (aii) Overall, stress suppressed pickup-related spiking activity of delay-tuned neurons suggesting that PFC neuron error signals carried by delay neurons are suppressed by stress (n = 17). Multiplexed reward (aiii, n = 18) and choice-related (aiv, n = 21) responses of delay-tuned neurons were also suppressed by stress. (b) Choice-related responses of reward-tuned multiplexing neurons are suppressed during stress (n = 27). *P < 0.05; **P < 0.01.

Article Snippet: Statistical Analyses Peri-event time histogram (PETH) analysis was used to determine the mean spiking probability on a trial-by-trial basis during each task event interval (250 ms bin, Devilbiss et al. 2012 ).

Techniques: Activity Assay, Multiplexing