Persistent activity in prefrontal cortex during trace eyelid conditioning: dissociating responses that reflect cerebellar output from those that do not.

Article date: 2013/12/16

PubMed ID: 2244977

Journal name: The Journal of neuroscience : the official journal of the Society for Neuroscience (ISSN: 1529-2401)

DOI: 10.1523/JNEUROSCI.1238-13.2013


Persistent neural activity, responses that outlast the stimuli that evoke them, plays an important role in neural computations and possibly in processes, such as working memory. Recent studies suggest that trace eyelid conditioning, which involves a temporal gap between the conditioned and unconditioned stimuli (the trace interval), requires persistent neural activity in a region of medial prefrontal cortex (mPFC). This persistent activity, which could be conveyed to cerebellum via a pathway through pons, may engage the cerebellum and allow for the expression of conditioned responses. Given the substantial reciprocity observed among many brain regions, it is essential to demonstrate that persistent responses in mPFC neurons are not simply a reflection of cerebellar feedback to the forebrain, leaving open the possibility that such responses could serve as input to the cerebellum. This concern is highlighted by studies showing that hippocampal learning-related activity is abolished by cerebellar inactivation. We inactivated the cerebellum while recording single-unit activity from the mPFC of rabbits trained with a forebrain-dependent trace eyelid conditioning procedure. We report that, whereas the responses of cells that show an onset of increased spike activity during the trace interval were abolished by cerebellar inactivation, persistent responses that begin during the conditioned stimulus and persisted into the trace interval were unaffected. Therefore, conditioned stimulus-evoked persistent responses remain the strongest candidate input pattern to support the cerebellar expression of learned responses.

Author List: Siegel Jennifer J, Mauk Michael D

Publication Types: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't

Substances mentioned in the article: GABA-A Receptor Agonists; Muscimol;

Mesh terms: Action Potentials/drug effects; Animals; Brain Mapping; Cerebellum/drug effects; Conditioning, Classical/drug effects; Conditioning, Eyelid/drug effects; GABA-A Receptor Agonists/pharmacology; Male; Muscimol/pharmacology; Neural Pathways/drug effects; Neurons/classification; Prefrontal Cortex/cytology; Rabbits; Time Factors;

Citations: - 2395531

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