Effect of Oral Nicotine Administration on Expression of Neuropeptide Y and Neuropeptide Y2 Receptor in Rat Brain


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Birdogan A., Salur E., Ozturk M., Aypar B., Keser A. , Kanit L. , ...More

ACTA PHYSIOLOGICA, vol.227, pp.37, 2019 (Journal Indexed in SCI) identifier

  • Publication Type: Article / Abstract
  • Volume: 227
  • Publication Date: 2019
  • Title of Journal : ACTA PHYSIOLOGICA
  • Page Numbers: pp.37
  • Keywords: Amygdala, hippocampus, neuropeptide Y, nicotine, NPY-Y2, prefrontal cortex

Abstract

Neuropeptide Y (NPY) and its receptors are involved in the regulation of mood, stress, and anxiety. In parallel,
NPY signaling may play a vital role in the negative affective state induced by drug withdrawal. This study
examined the changes in the transcript levels of NPY, Y1, Y2, and Y5 receptors in the mesocorticolimbic system
during chronic nicotine exposure and withdrawal. Rats were administered with nicotine (initial dose: 25 μg/ml,
maintenance dose: 50 μg/ml, free base) in drinking water for 12 weeks. Control group received only tap water. In
the final week of the study, some of the nicotine-treated animals continued to receive nicotine (0-W), whereas
some were withdrawn for either 24 (24-W) or 48 (48-W) h. All animals were decapitated after the evaluation of
somatic signs (frequency of gasps, eye blinks, ptosis, shakes, teeth chatter) and the duration of locomotor activity
and immobility. mRNA levels of NPY, Y1, Y2, and Y5 receptors in the mesocorticolimbic system were measured
by quantitative real-time PCR (qRT-PCR). Results showed that nicotine withdrawal increased overall somatic
signs. Moreover, chronic nicotine treatment increased the duration of locomotor activity, whereas withdrawal
increased the duration of immobility. qRT-PCR analysis revealed that chronic nicotine treatment increased NPY
mRNA levels in the hippocampus. On the other hand, 24- and 48-h withdrawals increased NPY mRNA levels in
the amygdala and medial prefrontal cortex (mPFC), Y1 and Y2 mRNA levels in the nucleus accumbens and mPFC,
and Y5 mRNA levels in the mPFC. These findings suggest that nicotine withdrawal enhances NPY signaling in the
mesocorticolimbic system, which could be an important mechanism involved in regulating the negative affective
state triggered during nicotine withdrawal.