Warning: file_get_contents(https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=23034771
&cmd=llinks): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 215
Dynamic coding of dorsal hippocampal neurons between tasks that differ in
structure and memory demand
#MMPMID23034771
Hallock HL
; Griffin AL
Hippocampus
2013[Feb]; 23
(2
): 169-86
PMID23034771
show ga
Hippocampal place fields show remapping between environments that contain
sufficiently different contextual features, a phenomenon that may reflect a
mechanism for episodic memory formation. Previous studies have shown that place
fields remap to changes in the configuration of visual landmarks in an
environment. Other experiments have demonstrated that remapping can occur with
experience, even when the visual features of an environment remain stable. A
special case of remapping may be trajectory coding, the tendency for hippocampal
neurons to exhibit different firing rates depending upon recently visited or
upcoming spatial locations. To further delineate the conditions under which
different task features elicit remapping, we recorded from place cells in dorsal
CA1 of hippocampus while rats switched between tasks that differed in memory
demand and task structure; continuous spatial alternation (CA), delayed spatial
alternation (DA), and tactile-visual conditional discrimination (CD). Individual
hippocampal neurons and populations of simultaneously recorded neurons showed
coherent remapping between CA and CD. However, task remapping was rarely seen
between DA and CD. Analysis of individual units revealed that even though the
population retained a coherent representation of task structure across the DA and
CD tasks, the majority of individual neurons consistently remapped at some point
during recording sessions. In contrast with previous studies, trajectory coding
on the stem of the T-maze was virtually absent during all of the tasks,
suggesting that experience with multiple tasks in the same environment reduces
the likelihood that hippocampal neurons will represent distinct trajectories.
Trajectory coding was, however, observed during the delay period of DA. Whether
place fields change in response to task or trial type or remain stable within the
same environment may depend on which aspects of the context are most salient or
relevant to behavior.
free
free
free
