Differential contribution of dorsal and ventral hippocampus to trace and delay fear conditioning
Hippocampus. 2009-01-01; 19(1): 33-44
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1. Hippocampus. 2009 Jan;19(1):33-44. doi: 10.1002/hipo.20473.
Differential contribution of dorsal and ventral hippocampus to trace and delay
Esclassan F(1), Coutureau E, Di Scala G, Marchand AR.
(1)Université de Bordeaux, Centre de Neurosciences Intégratives et Cognitives,
C.N.R.S. UMR 5228, Talence, France.
Trace conditioning relies on the maintained representation of a stimulus across a
trace interval, and may involve a persistent trace of the conditioned stimulus
(CS) and/or a contribution of contextual conditioning. The role of hippocampal
structures in these two types of conditioning was studied by means of pretraining
lesions and reversible inactivation of the hippocampus in rats. Similar levels of
conditioning to a tone CS and to the context were obtained with a trace interval
of 30 s. Neurotoxic lesions of the whole hippocampus or reversible muscimol
inactivation of the ventral hippocampus impaired both contextual and tone
freezing in both trace- and delay-conditioned rats. Dorsal hippocampal injections
impaired contextual freezing and trace conditioning, but not delay conditioning.
No dissociation between trace and contextual conditioning was observed under any
of these conditions. Altogether, these data indicate that the ventral and dorsal
parts of the hippocampus compute different aspects of trace conditioning, with
the ventral hippocampus being involved in fear and anxiety processes, and the
dorsal hippocampus in the temporal and contextual aspects of event
Copyright 2008 Wiley-Liss, Inc.
PMID: 18683846 [Indexed for MEDLINE]