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Lesions of the ventral hippocampus, but not the dorsal hippocampus, impair conditioned fear expression and inhibitory avoidance on the elevated T-maze.
Neurobiol Learn Mem. 2004 May; 81(3):172-84.NL

Abstract

The hippocampus has been suggested to be involved in spatial (or configural) memory and also in the inhibition of certain response or goal alternatives. An increasing number of anatomical, physiological, and behavioral studies indicate that the hippocampus is functionally heterogeneous along the dorsal-ventral axis. Identification of distinct behavioral roles for the dorsal (DH) and ventral (VH) hippocampus may resolve differences between the various theoretical accounts of hippocampal function. The present study examined the effects of electrolytic lesions restricted to the DH or VH on fear-conditioned freezing, passive avoidance on the elevated T-maze (ETM) test of anxiety, and general activity in male Sprague-Dawley (Charles-River derived) albino rats. We found that rats with lesions of the VH, but not DH showed reduced freezing to both context and tone conditioned stimuli (CS). Rats with VH lesions also showed a reduced latency to emerge from the enclosed arm on trials 2 and 3 of the ETM (indicating reduced anxious behavior), while having no effect on the latency to escape from the open arms on trial 4. There were no differences in activity between the groups. These results indicate that the VH and DH are differentially involved in passive avoidance on the ETM and conditioned freezing to context and tone CS. We suggest that the VH may be specifically involved in modulating goal-oriented, defensive behavior expression through hypothalamic and amygdaloid connections.

Authors+Show Affiliations

Department of Psychology, Northern Illinois University, DeKalb, IL 60115, USA. mtrivedi@niu.eduNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article

Language

eng

PubMed ID

15082019

Citation

Trivedi, Mehul A., and Gary D. Coover. "Lesions of the Ventral Hippocampus, but Not the Dorsal Hippocampus, Impair Conditioned Fear Expression and Inhibitory Avoidance On the Elevated T-maze." Neurobiology of Learning and Memory, vol. 81, no. 3, 2004, pp. 172-84.
Trivedi MA, Coover GD. Lesions of the ventral hippocampus, but not the dorsal hippocampus, impair conditioned fear expression and inhibitory avoidance on the elevated T-maze. Neurobiol Learn Mem. 2004;81(3):172-84.
Trivedi, M. A., & Coover, G. D. (2004). Lesions of the ventral hippocampus, but not the dorsal hippocampus, impair conditioned fear expression and inhibitory avoidance on the elevated T-maze. Neurobiology of Learning and Memory, 81(3), 172-84.
Trivedi MA, Coover GD. Lesions of the Ventral Hippocampus, but Not the Dorsal Hippocampus, Impair Conditioned Fear Expression and Inhibitory Avoidance On the Elevated T-maze. Neurobiol Learn Mem. 2004;81(3):172-84. PubMed PMID: 15082019.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Lesions of the ventral hippocampus, but not the dorsal hippocampus, impair conditioned fear expression and inhibitory avoidance on the elevated T-maze. AU - Trivedi,Mehul A, AU - Coover,Gary D, PY - 2003/08/06/received PY - 2004/02/09/revised PY - 2004/02/12/accepted PY - 2004/4/15/pubmed PY - 2004/8/4/medline PY - 2004/4/15/entrez SP - 172 EP - 84 JF - Neurobiology of learning and memory JO - Neurobiol Learn Mem VL - 81 IS - 3 N2 - The hippocampus has been suggested to be involved in spatial (or configural) memory and also in the inhibition of certain response or goal alternatives. An increasing number of anatomical, physiological, and behavioral studies indicate that the hippocampus is functionally heterogeneous along the dorsal-ventral axis. Identification of distinct behavioral roles for the dorsal (DH) and ventral (VH) hippocampus may resolve differences between the various theoretical accounts of hippocampal function. The present study examined the effects of electrolytic lesions restricted to the DH or VH on fear-conditioned freezing, passive avoidance on the elevated T-maze (ETM) test of anxiety, and general activity in male Sprague-Dawley (Charles-River derived) albino rats. We found that rats with lesions of the VH, but not DH showed reduced freezing to both context and tone conditioned stimuli (CS). Rats with VH lesions also showed a reduced latency to emerge from the enclosed arm on trials 2 and 3 of the ETM (indicating reduced anxious behavior), while having no effect on the latency to escape from the open arms on trial 4. There were no differences in activity between the groups. These results indicate that the VH and DH are differentially involved in passive avoidance on the ETM and conditioned freezing to context and tone CS. We suggest that the VH may be specifically involved in modulating goal-oriented, defensive behavior expression through hypothalamic and amygdaloid connections. SN - 1074-7427 UR - https://www.unboundmedicine.com/medline/citation/15082019/Lesions_of_the_ventral_hippocampus_but_not_the_dorsal_hippocampus_impair_conditioned_fear_expression_and_inhibitory_avoidance_on_the_elevated_T_maze_ DB - PRIME DP - Unbound Medicine ER -