Effects of apomorphine, clonidine or 5-methoxy-NN-dimethyltryptamine on approach and escape components of lateral hypothalamic and mesencephalic central gray stimulation in two inbred strains of mice.
Pharmacology, biochemistry, and behavior January 1, 1983 DOI: 10.1016/0091-3057(83)90256-3 via PubMed
Summary
AI-generated from the abstractInjecting mice with drugs that affect dopamine, serotonin, or norepinephrine alters their approach and escape behaviors triggered by brain stimulation. Apomorphine, which mimics dopamine, slowed both approach and escape reactions, more so in BALB/c mice. Clonidine, which mimics norepinephrine, sped up approach only in BALB/c mice. 5-m-DMT, which mimics serotonin, slowed escape in DBA/2 mice only. These results suggest that dopamine regulates escape from midbrain stimulation, serotonin modulates escape from both brain areas, and norepinephrine influences the appetitive component of hypothalamic stimulation. Approach and escape reactions depend on separate neuronal populations.
Study at a glance
| Characteristics | Experimental study Peer reviewed |
|---|---|
| Population | BALB/c and DBA/2 mice |
| Interventions | apomorphine clonidine 5-methoxy-NN-dimethyltryptamine |
| Dose | increasing doses |
| Citations | 11 |
| Key finding | Dopamine modulates escape from central gray stimulation, serotonin modulates escape from both lateral hypothalamus and central gray, and norepinephrine influences the appetitive component of lateral hypothalamic stimulation. |
Abstract
The effects of intraperitoneal injections of increasing doses of apomorphine, clonidine or 5-methoxy-NN-dimethyltryptamine (5-m-DMT) on approach and escape reactions induced by lateral hypothalamic (LH) or mesencephalic central gray (CG) stimulation were compared in BALB/c and DBA/2 mice. Apomorphine increased both the approach latency for LH stimulation and the escape latency for CG stimulation; the BALB/c strain was more reactive than DBA/2 animals. Clonidine reduced the approach latency for LH stimulation only in the BALB/c strain. 5-m-DMT increased escape latency both for LH and CG stimulation only in the DBA/2 strain. These results suggest that the neurochemical regulation of escape reactions respectively generated by LH or CG activation is partially different: dopamine seems to be involved only in CG aversion, whereas serotonin (5-HT) modulates both LH and CG escape reactions. Moreover, our results demonstrate a noradrenergic influence on the appetitive component of LH stimulation. Finally, they confirm that approach and escape reactions, particularly when induced from lateral hypothalamus, depend on distinct neuronal populations.