Prenatal stress and subsequent exposure to chronic mild stress influence dendritic spine density and morphology in the rat medial prefrontal cortex.
BACKGROUND
Both prenatal stress (PS) and postnatal chronic mild stress (CMS) are associated with behavioral and mood disturbances in humans and rodents. The aim of this study was to reveal putative PS- and/or CMS-related changes in basal spine morphology and density of pyramidal neurons in the rat medial prefrontal cortex (mPFC).


RESULTS
We show that rats exposed to PS and/or CMS display changes in the morphology and number of basal spines on pyramidal neurons in the mPFC. CMS had a negative effect on spine densities, particularly on spines of the mushroom type, which are considered to form stronger and more stable synapses than other spine types. PS alone did not affect spine densities, but had a negative effect on the ratio of mushroom spines. In addition, PS seemed to make rats less responsive to some of the negative effects of CMS, which supports the notion that PS represents a predictive adaptive response.


CONCLUSIONS
The observed changes may represent a morphological basis of PS- and CMS-related disturbances, and future studies in the field should not only consider total spine densities, but also separate between different spine types.
Michelsen
Kimmo A
KA
Department of Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands. k.michelsen@np.unimaas.nl
van den Hove
Daniël L A
DL
Schmitz
Christoph
C
Segers
Olivier
O
Prickaerts
Jos
J
Steinbusch
Harry W M
HW
D000818:Animals; D000831:Animals, Newborn; D048430:Cell Shape / Q000502:physiology; D002908:Chronic Disease; D049229:Dendritic Spines / Q000473:pathology*; D005260:Female; D019044:Image Cytometry; D008297:Male; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D019964:Mood Disorders / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D017397:Prefrontal Cortex / Q000002:abnormalities / Q000473:pathology* / Q000503:physiopathology; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000473:pathology* / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013312:Stress, Physiological / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D013569:Synapses / Q000473:pathology; D009435:Synaptic Transmission / Q000502:physiology