Raphe-septal neurons changes in sensitivity to desipramine following an early septal lesion in the rat

• Published in: Progress in neuro-psychopharmacology & biological psychiatry Vol. 20; no. 8; pp. 1427 - 1434
• Main Authors: Molina, Miguel, Diaz-Meza, Jose Luis, Saavedra, Margarita, Ortiz, Maribel, Contreras, Carlos M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.11.1996; Elsevier
• Subjects: Animals; antidepressants; Antidepressive Agents, Tricyclic - pharmacology; Biological and medical sciences; Brain Injuries - physiopathology; desipramine; Desipramine - pharmacology; dorsal raphe nucleus; early septal lesion; Electric Stimulation; Electrophysiology; Female; hippocampus; Iontophoresis; lateral septal nuclei; limbic; Medical sciences; Membrane Potentials - physiology; Neurons - drug effects; Neuropharmacology; Pharmacology. Drug treatments; Psychoanaleptics: cns stimulant, antidepressant agent, nootropic agent, mood stabilizer..., (alzheimer disease); Psychology. Psychoanalysis. Psychiatry; Psychopharmacology; Raphe Nuclei - cytology; Raphe Nuclei - physiology; Rats; Rats, Wistar; dorsal raphe nucleus; hippocampus; early septal lesion; dorsal raphe nucleus (DRN); antidepressants; lateral septal nuclei; limbic; lateral septal nuclei (LSN); desipramine; desipramine (DMI); Intraperitoneal administration; Rat; Desipramine; Psychotropic; Septum nucleus; Rodentia; Central nervous system; Electrophysiology; Midbrain; Action potential; Limbic system; Tricyclic compound; Postnatal development; Vertebrata; Mammalia; Animal; Intracerebral administration; Antidepressant agent; Medulla oblongata; Raphe nucleus; Lesion; Mechanism of action; Brain (vertebrata); Rhinencephalon
• ISSN: 0278-5846; 1878-4216
• DOI: 10.1016/S0278-5846(96)00137-6

1. 1. The ekctrophysiological responsivity to desipramine (DMI) applied by systemic or local route was tested in Wistar female rats submitted to a wide lesion in the lateral septal area on the 8th day after birth. 2. 2. One year after a septal lesion, the dorsal raphe nucleus (DRN) stimulation produced an initial brief response in lateral septal and CA1/CA3 neurons. In the control and sham-lesion groups, most recordings showed only this initial brief response (non-late responding neurons); however, in the lesion group most of the recorded neurons showed an aftenh'scharge. 3. 3. DMI (2.14 mg/kg, 21 days, i.p.) increased the firing rate in septal and CA1/CA3 non-late responding neurons. In the equivalent septal neurons from lesion group, DMI produced the inverse effect, i.e., a decreased firing rate. 4. 4. In septal non-late responding neurons, DMI (2 mM; 10–15 nAmps, 0.5 sec) applied by microkmtopnoresis increased the firing rate only after long-term systemic DMI impregnation. The response to locally applied DMI did not occur in the lesion group even after long-term DMI treatment. 5. 5. In conclusion, an early lateral septal lesion canceled the response of intermediate-dorsal septal neurons to DMI applied by systemic and local routes.