The long-term effects of maternal deprivation on the number and size of inhibitory interneurons in the rat amygdala and nucleus accumbens

IntroductionThere is an increasing evidence supporting the hypothesis that traumatic experiences during early developmental periods might be associated with psychopathology later in life. Maternal deprivation (MD) in rodents has been proposed as an animal model for certain aspects of neuropsychiatric disorders.MethodsTo determine whether early-life stress leads to changes in GABAergic, inhibitory interneurons in the limbic system structures, specifically the amygdala and nucleus accumbens, 9-day-old Wistar rats were exposed to a 24 h MD. On postnatal day 60 (P60), the rats were sacrificed for morphometric analysis and their brains were compared to the control group.ResultsResults show that MD affect GABAergic interneurons, leading to the decrease in density and size of the calcium-binding proteins parvalbumin-, calbindin-, and calretinin-expressing interneurons in the amygdala and nucleus accumbens.DiscussionThis study indicates that early stress in life leads to changes in the number and morphology of the GABAergic, inhibitory interneurons in the amygdala and nucleus accumbens, most probably due to the loss of neurons during postnatal development and it further contributes to understanding the effects of maternal deprivation on brain development

Anatomically high division of sciatic nerve and its clinical significance

Background / Aim The sciatic nerve (SN) is a mixed nerve formed in pelvis by joining of L4 - S3 anterior spinal nerve roots. SN can be under the pressure in different regions throughout its course. However, the most frequent site of impingement is under the piriformis muscle which causes the occurrence of piriformis syndrome. High division of SN has its relevance considering the fact that it leads to the compression of nerve resulting in piriformis syndrome. The aim of this study was to determine the connection between anatomical parameters of pelvis and high division of SN, which is considered to be one of the most common causes of piriformis syndrome in both genders. Methods This study was conducted on 28 formalin fixed cadavers of both genders at the Institute of Anatomy, Faculty of Medicine, University of Belgrade (Belgrade, Serbia) and the Department of Anatomy, School of Medicine, University of St Andrews (St Andrews, United Kingdom). For the measuring of required dimensions, we used a ruler and a caliper. Results A statistically significant difference in the values of bispinal and bituberal lines was observed. A high division of SN was found on 58.33% of the male cadavers and 80% of the female cadavers. A statistically significant difference in the mean value of the bituberal line between the male and female sex was also recognised.Conclusion The connection between the anatomical parameters of the pelvis and the level of division of the SN is confirmed. Although on the basis of the results it could be assumed that people with smaller pelvic dimensions would have greater likelihood of developing a piriformis syndrome, the other factors, such as biomechanics related to a wider 'Q angle' in women that could result in a higher incidence of piriformis syndrome, should also be considered

Anatomically high division of sciatic nerve and its clinical significance

This study was supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia (Grant III41020).Background / Aim. The sciatic nerve (SN) is a mixed nerve formed in pelvis by joining of L4 - S3 anterior spinal nerve roots. SN can be under the pressure in different regions throughout its course. However, the most frequent site of impingement is under the piriformis muscle which causes the occurrence of piriformis syndrome. High division of SN has its relevance considering the fact that it leads to the compression of nerve resulting in piriformis syndrome. The aim of this study was to determine the connection between anatomical parameters of pelvis and high division of SN, which is considered to be one of the most common causes of piriformis syndrome in both genders. Methods. This study was conducted on 28 formalin fixed cadavers of both genders at the Institute of Anatomy, Faculty of Medicine, University of Belgrade (Belgrade, Serbia) and the Department of Anatomy, School of Medicine, University of St Andrews (St Andrews, United Kingdom). For the measuring of required dimensions, we used a ruler and a caliper. Results. A statistically significant difference in the values of bispinal and bituberal lines was observed. A high division of SN was found on 58.33% of the male cadavers and 80% of the female cadavers. A statistically significant difference in the mean value of the bituberal line between the male and female sex was also recognised. Conclusion. The connection between the anatomical parameters of the pelvis and the level of division of the SN is confirmed. Although on the basis of the results it could be assumed that people with smaller pelvic dimensions would have greater likelihood of developing a piriformis syndrome, the other factors, such as biomechanics related to a wider 'Q angle' in women that could result in a higher incidence of piriformis syndrome, should also be considered.Publisher PDFPeer reviewe

Maternal deprivation in rats decreases the expression of interneuron markers in the neocortex and hippocampus

Early life stress has profound effects on the development of the central nervous system. We exposed 9-day-old rat pups to a 24 h maternal deprivation (MD) and sacrificed them as young adults (60-day-old), with the aim to study the effects of early stress on forebrain circuitry. We estimated numbers of various immunohistochemically defined interneuron subpopulations in several neocortical regions and in the hippocampus. MD rats showed reduced numbers of parvalbumin-expressing interneurons in the CA$_1$ region of the hippocampus and in the prefrontal cortex, compared with controls. Numbers of reelin-expressing and calretinin-expressing interneurons were also reduced in the CA1 and CA$_3$ hippocampal areas, but unaltered in the neocortex of MD rats. The number of calbinin-expressing interneurons in the neocortex was similar in the MD rats compared with controls. We analyzed cell death in 15-day-old rats after MD and found no difference compared to control rats. Thus, our results more likely reflect the downregulation of markers than the actual loss of interneurons. To investigate synaptic activity in the hippocampus we immunostained for glutamatergic and inhibitory vesicular transporters. The number of inhibitory synapses was decreased in the CA$_1$ and CA$_3$ regions of the hippocampus in MD rats, with the normal number of excitatory synapses. Our results indicate complex, cell type-specific, and region-specific alterations in the inhibitory circuitry induced by maternal deprivation. Such alterations may underlie symptoms of MD at the behavioral level and possibly contribute to mechanisms by which early life stress causes neuropsychiatric disorders, such as schizophrenia