The neurobiology of thalamic amnesia: Contributions of medial thalamus and prefrontal cortex to delayed conditional discrimination.

Academic Article

Abstract

  • Although medial thalamus is well established as a site of pathology associated with global amnesia, there is uncertainty about which structures are critical and how they affect memory function. Evidence from human and animal research suggests that damage to the mammillothalamic tract and the anterior, mediodorsal (MD), midline (M), and intralaminar (IL) nuclei contribute to different signs of thalamic amnesia. Here we focus on MD and the adjacent M and IL nuclei, structures identified in animal studies as critical nodes in prefrontal cortex (PFC)-related pathways that are necessary for delayed conditional discrimination. Recordings of PFC neurons in rats performing a dynamic delayed non-matching-to position (DNMTP) task revealed discrete populations encoding information related to planning, execution, and outcome of DNMTP-related actions and delay-related activity signaling previous reinforcement. Parallel studies recording the activity of MD and IL neurons and examining the effects of unilateral thalamic inactivation on the responses of PFC neurons demonstrated a close coupling of central thalamic and PFC neurons responding to diverse aspects of DNMTP and provide evidence that thalamus interacts with PFC neurons to give rise to complex goal-directed behavior exemplified by the DNMTP task.
  • Authors

  • Mair, Robert G
  • Miller, Rikki LA
  • Wormwood, Benjamin A
  • Francoeur, Miranda J
  • Onos, Kristen D
  • Gibson, Brett
  • Status

    Publication Date

  • July 2015
  • Keywords

  • Amnesia
  • Animals
  • Conditional discrimination
  • Conditioning (Psychology)
  • DNMTP
  • Discrimination (Psychology)
  • Executive Function
  • Humans
  • Intralaminar Thalamic Nuclei
  • Intralaminar nuclei
  • Korsakoff Syndrome
  • Mediodorsal Thalamic Nucleus
  • Mediodorsal nucleus
  • Memory
  • Neural Pathways
  • Neurons
  • Prefrontal Cortex
  • Prefrontal cortex
  • Thalamic amnesia
  • Digital Object Identifier (doi)

    Start Page

  • 161
  • End Page

  • 174
  • Volume

  • 54