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Prenatal Exposure to Morphine Enhances Excitability in Locus Coeruleus Neurons

Overview
Specialties Neurology
Physiology
Date 2022 Jun 8
PMID 35674919
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Abstract

Opioid abuse during pregnancy may have noteworthy effects on the child's behavioral, emotional and cognitive progression. In this study, we assessed the effect of prenatal exposure to morphine on electrophysiological features of locus coeruleus (LC) noradrenergic neurons which is involved in modulating cognitive performance. Pregnant dams were randomly divided into two groups, that is a prenatal saline treated and prenatal morphine-treated group. To this end, on gestational days 11-18, either morphine or saline (twice daily, s.c.) was administered to pregnant dams. Whole-cell patch-clamp recordings were conducted on LC neurons of male offspring. The evoked firing rate, instantaneous frequency and action potentials half-width, and also input resistance of LC neurons significantly increased in the prenatal morphine group compared to the saline group. Moreover, action potentials decay slope, after hyperpolarization amplitude, rheobase current, and first spike latency were diminished in LC neurons following prenatal exposure to morphine. In addition, resting membrane potential, rise slope, and amplitude of action potentials were not changed by prenatal morphine exposure. Together, the current findings show a significant enhancement in excitability of the LC neurons following prenatal morphine exposure, which may affect the release of norepinephrine to other brain regions and/or cognitive performances of the offspring.

References
1.
Aghajanian G . Tolerance of locus coeruleus neurones to morphine and suppression of withdrawal response by clonidine. Nature. 1978; 276(5684):186-8. DOI: 10.1038/276186a0. View

2.
Ahmadi-Soleimani S, Azizi H, Gompf H, Semnanian S . Role of orexin type-1 receptors in paragiganto-coerulear modulation of opioid withdrawal and tolerance: A site specific focus. Neuropharmacology. 2017; 126:25-37. DOI: 10.1016/j.neuropharm.2017.08.024. View

3.
Alaee E, Moazen P, Pattij T, Semnanian S, Azizi H . Prenatal exposure to morphine impairs attention and impulsivity in adult rats. Psychopharmacology (Berl). 2021; 238(10):2729-2741. DOI: 10.1007/s00213-021-05888-7. View

4.
Ali A, Bannister A, Thomson A . Robust correlations between action potential duration and the properties of synaptic connections in layer 4 interneurones in neocortical slices from juvenile rats and adult rat and cat. J Physiol. 2007; 580(Pt 1):149-69. PMC: 2075440. DOI: 10.1113/jphysiol.2006.124214. View

5.
Amaral D, FOSS J . Locus coeruleus lesions and learning. Science. 1975; 188(4186):377-8. DOI: 10.1126/science.1118734. View