Diário da Espinha

Modulation of Pain by Naloxone and a Possible Role of Neurotransmitters with Selective Lesion of Septal Nuclei

Abstract

Prakash M. Somade, Atul R. Chopade, and Shivaji V. Brid

Septum occupies a strategic position in limbic system and has been implicated in variety of behaviors. Present study was designed to evaluate the role of medial septum in modulation of pain and explore the role of neurotransmitters.

The present study was divided in two parts in first part the tail flick latencies were observed in rats with septal lesions and compared with sham operated ones. While in the second part, the effect of intraseptal injections of neurotransmitters and naloxone on tail flick latencies of cannulated rats was recorded after intraseptal lesions.

It was observed that the septal lesions decrease pain threshold. The interaseptal injection of Acetylcholine (5 μg to 20 μg) and Naloxone (5 μg to 20 μg) increases pain threshold. While the Interaseptal injection of Noradrenaline and Scopolamine decreases pain threshold.

The findings of the present study suggest that septum may be involved in modulation of pain. The neurotransmitters like Acetylcholine, Noradrenaline and opioid peptides may have an individual or collective role to play in the observed pain modulation.