title: No Evidence for Sex Differences in the Electrophysiological Properties and Excitatory Synaptic Input onto Nucleus Accumbens Shell Medium Spiny Neurons.
abstract: Sex differences exist in how the brain regulates motivated behavior and reward, both in normal and pathological contexts. Investigations into the underlying neural mechanisms have targeted the striatal brain regions, including the dorsal striatum and nucleus accumbens core and shell. These investigations yield accumulating evidence of sexually different electrophysiological properties, excitatory synaptic input, and sensitivity to neuromodulator/hormone action in select striatal regions both before and after puberty. It is unknown whether the electrical properties of neurons in the nucleus accumbens shell differ by sex, and whether sex differences in excitatory synaptic input are present before puberty. To test the hypothesis that these properties differ by sex, we performed whole-cell patch-clamp recordings on male and female medium spiny neurons (MSNs) in acute brain slices obtained from prepubertal rat nucleus accumbens shell. We analyzed passive and active electrophysiological properties, and miniature EPSCs (mEPSCs). No sex differences were detected; this includes those properties, such as intrinsic excitability, action potential afterhyperpolarization, threshold, and mEPSC frequency, that have been found to differ by sex in other striatal regions and/or developmental periods. These findings indicate that, unlike other striatal brain regions, the electrophysiological properties of nucleus accumbens shell MSNs do not differ by sex. Overall, it appears that sex differences in striatal function, including motivated behavior and reward, are likely mediated by other factors and striatal regions.
authors.affiliation: Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695; W.M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, North Carolina 27695; Graduate Program in Physiology, North Carolina State University, Raleigh, North Carolina 27695.
authors.forename: Jaime A
authors.initials: JA
authors.lastname: Willett
authors.affiliation: Department of Biological Sciences, North Carolina State University , Raleigh, North Carolina 27695.
authors.forename: Tyler
authors.initials: T
authors.lastname: Will
authors.affiliation: Department of Biological Sciences, North Carolina State University , Raleigh, North Carolina 27695.
authors.forename: Caitlin A
authors.initials: CA
authors.lastname: Hauser
authors.affiliation: Department of Biological Sciences, North Carolina State University , Raleigh, North Carolina 27695.
authors.forename: David M
authors.identifier: 0000-0003-4612-7667
authors.initials: DM
authors.lastname: Dorris
authors.affiliation: Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695; W.M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, North Carolina 27695.
authors.forename: Jinyan
authors.initials: J
authors.lastname: Cao
authors.affiliation: Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695; W.M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, North Carolina 27695; Center for Human Health and the Environment, Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina 27695.
authors.forename: John
authors.initials: J
authors.lastname: Meitzen
mesh_terms: D000200:Action Potentials; D000818:Animals; D019706:Excitatory Postsynaptic Potentials; D005260:Female; D007395:Interneurons / Q000502:physiology*; D008297:Male; D008564:Membrane Potentials; D055369:Miniature Postsynaptic Potentials; D009714:Nucleus Accumbens / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012727:Sex Characteristics
keywords: genetic sex; intrinsic electrophysiological properties; mEPSC; male and female rats; medium spiny neuron; striatum