Nuclei wriggle in the cells of the follicle epithelium of the Drosophila pre-vitellogenic egg primordia. Although similar phenomena have been reported for a number of cultured cell types and some neurons in the zebrafish embryo, the mechanism and importance of the process have remained unexplained. Wriggling involves successive sudden and random minor turns of the nuclei, approximately three tw...

The amygdala is the central component of a functional brain system regulating fear and emotional behaviors. Studies of the ontogeny of fear behaviors reveal the emergence of distinct fear responses at different postnatal ages. Here, we performed a stereological analysis of the rat amygdala to characterize the cellular changes underlying its normal structural development. Distinct amygdala nucle...

Over a 24-h period, groups of mice were given a single injection of colchicine (to collect blocked metaphases) and tritiated thymidine (to label nuclei synthesizing deoxyribonucleic acid). Epithelial nuclei in the oesophagus, trachea and ureter were examined and counted in paraffin sections: the duration of deoxyribonucleic acid synthesis (Ts) was calculated from the numbers of blocked metaphas...

Horseradish peroxidase (HRP) was injected into various nuclei of the amygdala in 50 rats. The retrograde axonal transport of HRP showed various connections arising from the hypothalamic nuclei and the basal forebrain. Neurons of the magnocellular preoptic nucleus send out amygdalopetal axons to all amygdaloid nuclei except the lateral nucleus. The amygdalopetal projections emerge from the large...

Few studies have investigated in vivo changes of the cholinergic basal forebrain in Alzheimer's disease (AD) and amnestic mild cognitive impairment (MCI), an at risk stage of AD. Even less is known about alterations of cortical projecting fiber tracts associated with basal forebrain atrophy. In this study, we determined regional atrophy within the basal forebrain in 21 patients with AD and 16 s...

The role of the dorsal basal and the central nuclei of the amygdala under two modes of foot-shock analgesia was studied in 45 Möll-Wistar rats. Four minutes of continuous foot-shock produced post-stress analgesia in control and in all lesioned rats, but 20 min of regularly intermittent foot-shock did not evoke analgesia in rats with central nucleus lesion. This result indicates different involv...