Chronic infusions of mecamylamine into the medial habenula: Effects on nicotine self-administration in rats.

Levin, Edward D

Wells, Corinne

Slade, Susan

Johnson, Joshua

Petro, Ann

Rezvani, Amir H

Rose, Jed E

2023-12-06T14:25:56Z

2023-12-06T14:25:56Z

2022-01

2023-12-06T14:25:56Z

The habenula is an epithalamic structure through which descending connections go from the telencephalon to the brainstem, putting it in a key location to provide feedback control over the ascending projections from the brainstem to the telencephalon. The medial habenula has a high concentration of nicotinic receptors. We assessed the role of medial habenular nicotinic receptors for nicotine self-administration (SA) in female young adult Sprague-Dawley rats. The rats had bilateral chronic infusion cannulae placed into the medial habenula nucleus. Each cannula was connected to a slow delivery osmotic minipump to chronically infuse mecamylamine (100 µg/side/day) or vehicle for four consecutive weeks. The rats were tested for nicotine SA for the first two weeks of mecamylamine infusion. Then, they had one week of enforced abstinence, during which they had no access to the nicotine SA. Finally, they had one week of resumed nicotine SA access. There was a significantly differential mecamylamine effects in animals with lower and higher pretreatment baseline nicotine SA. Rats with lower baseline nicotine SA levels showed a nearly significant mecamylamine-induced reduction in SA while those with higher baseline levels of SA showed a significant mecamylamine-induced increase in nicotine SA. This study determined that medial habenular nicotinic receptors are important for nicotine reinforcement. Baseline level of performance makes a crucial difference for the involvement of habenular mechanisms in nicotine reinforcement with nicotinic activation being important for maintaining nicotine self-administration for those with lower levels of baseline self-administration and the opposite effect with subjects with higher levels of baseline self-administration.

S0166-4328(21)00462-9

0166-4328

1872-7549

https://hdl.handle.net/10161/29481

eng

Elsevier BV

Behavioural brain research

10.1016/j.bbr.2021.113574

Habenula

Animals

Rats

Rats, Sprague-Dawley

Mecamylamine

Nicotine

Receptors, Nicotinic

Self Administration

Female

Infusions, Intraventricular

Reinforcement, Psychology

Chronic infusions of mecamylamine into the medial habenula: Effects on nicotine self-administration in rats.

Journal article

Levin, Edward D|0000-0002-5060-9602

113574

Duke

Nicholas School of the Environment

School of Medicine

Trinity College of Arts & Sciences

Basic Science Departments

Clinical Science Departments

Institutes and Centers

Pharmacology & Cancer Biology

Psychiatry & Behavioral Sciences

Duke Cancer Institute

Psychology & Neuroscience

Environmental Sciences and Policy

Institutes and Provost's Academic Units

University Institutes and Centers

Duke Institute for Brain Sciences

Initiatives

Duke Science & Society

Psychiatry & Behavioral Sciences, Behavioral Medicine & Neurosciences

Published

416