title: Reproductive experience modified dendritic spines on cortical pyramidal neurons to enhance sensory perception and spatial learning in rats.
abstract: Behavioral adaptations during motherhood are aimed at increasing reproductive success. Alterations of hormones during motherhood could trigger brain morphological changes to underlie behavioral alterations. Here we investigated whether motherhood changes a rat's sensory perception and spatial memory in conjunction with cortical neuronal structural changes. Female rats of different statuses, including virgin, pregnant, lactating, and primiparous rats were studied. Behavioral test showed that the lactating rats were most sensitive to heat, while rats with motherhood and reproduction experience outperformed virgin rats in a water maze task. By intracellular dye injection and computer-assisted 3-dimensional reconstruction, the dendritic arbors and spines of the layer III and V pyramidal neurons of the somatosensory cortex and CA1 hippocampal pyramidal neurons were revealed for closer analysis. The results showed that motherhood and reproductive experience increased dendritic spines but not arbors or the lengths of the layer III and V pyramidal neurons of the somatosensory cortex and CA1 hippocampal pyramidal neurons. In addition, lactating rats had a higher incidence of spines than pregnant or primiparous rats. The increase of dendritic spines was coupled with increased expression of the glutamatergic postsynaptic marker protein (PSD-95), especially in lactating rats. On the basis of the present results, it is concluded that motherhood enhanced rat sensory perception and spatial memory and was accompanied by increases in dendritic spines on output neurons of the somatosensory cortex and CA1 hippocampus. The effect was sustained for at least 6 weeks after the weaning of the pups.
authors: Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung, Taiwan.
authors: Jeng-Rung
authors: JR
authors: Chen
authors: Seh Hong
authors: SH
authors: Lim
authors: Sin-Cun
authors: SC
authors: Chung
authors: Yee-Fun
authors: YF
authors: Lee
authors: Yueh-Jan
authors: YJ
authors: Wang
authors: Guo-Fang
authors: GF
authors: Tseng
authors: Tsyr-Jiuan
authors: TJ
authors: Wang
mesh_terms: D000818:Animals; D049229:Dendritic Spines / Q000502:physiology; D005260:Female; D006624:Hippocampus / Q000502:physiology; D007774:Lactation; D009035:Mothers; D010465:Perception; D011247:Pregnancy; D017966:Pyramidal Cells / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley / Q000502:physiology*; D013003:Somatosensory Cortex / Q000502:physiology; D065853:Spatial Learning; D014886:Weaning