Estrogen-concentrating cells within cell groups of the medial preoptic area: sex differences and co-localization with galanin-immunoreactive cells.

Male and female rats have approximately equal numbers of estrogen(E)-concentrating cells within the medial preoptic area (MPOA). Several cell groups within this brain region are sexually dimorphic, however, and these groups may have sexually different numbers of E-containing cells; this, in turn, may reflect sex differences in neural-regulated functions. In order to study this possibility, the distribution of E-concentrating cells was determined using estrogen autoradiography. Except for the lateral portion of the medial preoptic nucleus (MPNl), the density of E-concentrating cells was 3-5-times higher within the most medially situated cell groups of the female than the male, i.e., within the anteroventral periventricular nucleus (AVPv), periventricular preoptic area (PVPO), medial portion of the medial preoptic nucleus (MPNm), and its central portion (MPNc). In addition, we determined whether E-concentrating cells also express the neuropeptide, galanin. An average of 13% of the E-concentrating cells were galanin positive, which represented 15% of the galanin-immunoreactive population. These results demonstrate a frank and dramatic sex difference in the distribution of E-concentrating cells within sexually dimorphic regions of the MPOA, and also suggest that an interaction between galanin and gonadal steroids may be an important means by which cells within the MPOA regulate reproductive function.

Degenerative changes in traumatic brain injury: post-injury magnetic resonance identified ventricular expansion compared to pre-injury levels.

Magnetic resonance (MR) scans obtained 42 days and 10 months post-injury were compared to scans obtained in similar planes three months prior to injury. In comparison to pre-injury scans, post-injury MR scan analysis demonstrated significant ventricular volume increase which is considered a measure of the degree of diffuse axonal injury. Most important, the trauma induced degenerative effects appeared to be quite complete by 42 days post-injury as there was little further degeneration that occurred between the 6 week and 10 month post-injury scans. This study demonstrates that in humans the majority of gross trauma-induced degenerative changes are complete by 6 weeks post-trauma.

Magnetic resonance identified ventricular dilation in traumatic brain injury: comparison of pre- and postin jury scan and postin jury results.

A case study is presented in which a patient received magnetic resonance (MR) imaging of the brain 3 months prior to a severe traumatic brain injury (TBI). The post-TBI MR findings are compared and contrasted with the pre-TBI MR images. The posttraumatic changes demonstrate a significant dilation of the ventricular system which reflects diffuse axonal injury and loss of brain substance. Correspondingly, the neuropsychological studies in this individual reflect global deficits which match the nonspecific, traumatically induced degenerative changes found in the postinjury MR scan. This case study is unique in that specific preinjury MR findings are available for direct comparison and quantitative analysis of TBI-associated changes in brain structure with neuropsychological outcome.

Neuropsychological outcome and quantitative image analysis of acute haemorrhage in traumatic brain injury: preliminary findings.

The effect on neuropsychological outcome of the number of acute haemorrhages, lesion volume, and lesion location in traumatic brain injury (TBI) was evaluated. Haemorrhagic lesion volume was associated with severity of injury. However, the number of petechial haemorrhages was not reliably associated with any of the clinical outcome measures. Likewise, despite the use of detailed morphometric methods to quantify volume, the acute lesion size did not significantly relate to neuropsychological sequelae. Furthermore, brain quadrant localization methods did not enhance outcome prediction. These results are discussed in the context of acute lesion analysis contrasted with chronic TBI-induced neuropathological changes associated with neuropsychological outcome.