Passive avoidance behavior in lean and obese rats with ventromedial hypothalamic lesions

Content Provider	Semantic Scholar
Author	King, Bruce M. Carrington, Clark D. Grossman, Sebastian P.
Copyright Year	1978
Abstract	Abstract Lean and obese rats with ventromedial hypothalamic lesions performed reliably worse than control animals in the acquisition of a step-down passive avoidance task. However, obese rats performed significantly better than lean VMH animals, which consistently leaped off the platform on the second and succeeding trials. While there were no significant differences between groups in the acquisition of a step-through passive avoidance task, lean and obese rats with VMH lesions took reliably longer than control animals to reach criterion when an identical step-through response had previously been reinforced (punishment-extinction of a one-way conditioned avoidance response). Both lean and obese VMH-damaged rats made more punished approach responses to water than control animals following water-deprivation to 88% of body weight, but only lean VMH rats made a significantly greater number of punished approach responses to liquid food than unoperated animals following food-deprivation to 88% of body weight. The number of punished consummatory responses appeared to be influenced by baseline intake. Among the animals tested in more than one paradigm, there was a significant positive correlation between the number of punished consummatory responses and the number of shocks received during punishment-extinction of the one-way CAR, but no relationship was observed between the performances in either of these and the step-down avoidance paradigm. The impaired passive avoidance behavior by rats with VMH lesions is attributed to both an inability to inhibit a previously reinforced response and a change in response tendencies to aversive stimuli.
Starting Page	57
Ending Page	65
Page Count	9
File Format	PDF HTM / HTML
DOI	10.1016/0031-9384(78)90203-2
PubMed reference number	643948
Journal	Medline
Volume Number	20
Alternate Webpage(s)	https://api.elsevier.com/content/article/pii/0031938478902032
Alternate Webpage(s)	https://www.sciencedirect.com/science/article/pii/0031938478902032?dgcid=api_sd_search-api-endpoint
Alternate Webpage(s)	https://doi.org/10.1016/0031-9384%2878%2990203-2
Journal	Physiology & Behavior
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article