Restoration of Emotional Stress Reactions in Rats Following Disruption of the Limbic Structures of the Brain by Delta-Sleep-Inducing Peptide
Koplik EV, Sudakov KV
Neuroscience and Behavioral Physiology. 1999;29(1): 45-51
Koplik-1999
This report describes studies of delta-sleep-inducing peptide in the mechanism of compensating
emotional behavior following disruption of a number of structures of the limbic complex
(the septum and amygdala). Studies were performed in male Wistar rats. Peptide was
given i.p. at a dose of 60 nmol/kg. The individual/typological characteristics of the rats' behavior
and their resistance to stress was predicted using an open field test. Emotional stress
was modeled by immobilizing the animals and applying electric shocks to the skin. Stress
was assessed in terms of survival, adrenal hypertrophy, and thymic involution in stress conditions.
Bilateral lesioning to brain structures was carried out by anodic polarization. The
results obtained showed that the septum and amygdala play a significant role in the mechanisms
of resistance to emotional stress. Bilateral disruption of these structures significantly
decreased the animals' resistance to emotional stress, producing alterations in behavior in
the open field test, increasing the lethality of acute emotional stress, and inducing changes
in stress marker organs (the adrenals and thymus) in stress conditions, as compared to controls.
Administration of peptide to animals with lesions to the septum or amygdala increased
their resistance to emotional stress, as indicated by open field test behavior, survival, and
adrenal and thymus weight in stress conditions. Thus, doses of delta-sleep-inducing peptide
partially reverse reductions in stress resistance in animals with lesions to structures of the
limbic complex.
