The effect of competitive and non-competitive NMDA receptor antagonists, ACPC and MK-801 on NPY and CRF-like immunoreactivity in the rat brain amygdala

• Published in: Neuropeptides (Edinburgh) 2001-10, Vol.35 (5-6), p.219-226
• Main Authors: WIERONSKA, J. M, BRANSKI, P, PAŁVCHA, A, SMIAŁOWSKA, M
• Format: Article
• Language: English
• Subjects: Amino Acids, Cyclic - metabolism; Amino Acids, Cyclic - pharmacology; Amygdala - cytology; Amygdala - drug effects; Amygdala - metabolism; Animals; Anxiety - metabolism; Biological and medical sciences; Corticotropin-Releasing Hormone - metabolism; Dizocilpine Maleate - metabolism; Dizocilpine Maleate - pharmacology; Glutamatergic system (aspartate and other excitatory aminoacids); Male; Medical sciences; Neurons - drug effects; Neurons - metabolism; Neuropeptide Y - metabolism; Neuropharmacology; Neuroprotective Agents - metabolism; Neuroprotective Agents - pharmacology; Neurotransmitters. Neurotransmission. Receptors; Pharmacology. Drug treatments; Rats; Rats, Wistar; Receptors, N-Methyl-D-Aspartate - antagonists & inhibitors; Receptors, N-Methyl-D-Aspartate - metabolism
• ISSN: 0143-4179; 1532-2785
• DOI: 10.1054/npep.2002.0874

Amygdala is the brain structure responsible for integrating all behavior connected with fear, and in this structure two neuropeptides, neuropeptide Y (NPY), corticoliberin (CRF) and the most abundant excitatory neurotransmitter glutamate seem to take part in the regulation of anxiety behavior. Our previous studies showed the modulation of NPY and CRF expression by classical neurotransmitters in some brain structures, therefore in the present study we investigated the effect of NMDA receptor antagonists on the expression of NPY and CRF immunoreactivity in the rat brain amygdala. A non-competitive NMDA receptor antagonist, MK-801, or a functional NMDA antagonist, ACPC were used. Brains were taken out and processed by immunohistochemical method using specific NPY or CRF antibodies. The staining intensity and density of IR neurons were evaluated under a microscope in amygdala sections. It was found that both MK-801 and ACPC induced a significant decrease in NPY-immunoreactivity in amygdala nerve cell bodies and terminals, which may suggest an increased release of this peptide. CRF-IR was decreased after ACPC only. The obtained results indicate that in the amygdala, the NMDA receptors mediated glutamatergic transmission may regulate NPY neurons.