The fine structure of the cat stria vascularis was studied with the electron microscope. It consists of three layers of epithelial cells in close association with intraepithelial capillaries. The cells of the superficial row have a convex luminal surface bordering on the cochlear duct lumen. The apical cytoplasm contains numerous coated vesicles and vesicular invaginations which are interpreted as a type of micropinocytosis. Deep infoldings of the plasmalemma divide the lower twothirds of these cells into thin compartments containing numerous mitochondria. It is suggested that marginal cells are well adapted by their fine structure to participate in regulation of the ion composition of endolymph. The cells of the intermediate and basal rows have pale cytoplasm and numerous processes. Ascending processes of the basal cells form cup-like structures which partially isolate each apical cell from the rest of the epithelium.The endothelium of the strial capillaries is not remarkable and no discontinuities of the endothelial lining were observed. The endothelial basement lamina sends out numerous extensions into a system of interconnected extracellular passages that permeate the epithelium. These are interpreted as pathways for the rapid diffusion of materials from the capillaries.

Early stimulation has been shown to produce long-lasting effects in many species. Prenatal exposure to some strong stressors may affect development of the nervous system leading to behavioral impairment in adult life. The purpose of the present work was to study the postnatal harmful effects of exposure to variable mild stresses in rats during pregnancy. Female Holtzman rats were submitted daily to one session of a chronic variable stress (CVS) during pregnancy (prenatal stress; PS group). Control pregnant rats (C group) were undisturbed. The pups of PS and C dams were weighed and separated into two groups 48 h after delivery. One group was maintained with their own dams (PS group, N = 70; C group, N = 36) while the other PS pups were cross-fostered with C dams (PSF group, N = 47) and the other C pups were cross-fostered with PS dams (CF group, N = 58). Pups were undisturbed until weaning (postnatal day 28). The male offspring underwent motor activity tests (day 28), enriched environment tests (day 37) and social interaction tests (day 42) in an animal activity monitor. Body weight was recorded on days 2, 28 and 60. The PS pups showed lower birth weight than C pups (Duncans test, P<0.05). The PS pups suckling with their stressed mothers displayed greater preweaning mortality (C: 23%, PS: 60%; c 2 test, P<0.05) and lower body weight than controls at days 28 and 60 (Duncans test, P<0.05 and P<0.01, respectively). The PS, PSF and CF groups showed lower motor activity scores than controls when tested at day 28 (Duncans test, P<0.01 for PS group and P<0.05 for CF and PSF groups). In the enriched environment test performed on day 37, between-group differences in total motor activity were not detected; however, the PS, CF and PSF groups displayed less exploration time than controls (Duncans test, P<0.05). Only the PS group showed impaired motor activity and impaired social behavior at day 42 (Duncans test, P<0.05). In fact, CVS treatment during gestation plus suckling with a previously stressed mother caused long-lasting physical and behavioral changes in rats. Cross-fostering PS-exposed pups to a dam which was not submitted to stress counteracted most of the harmful effects of the treatment. It is probable that prenatal stress plus suckling from a previously stressed mother can induce long-lasting changes in the neurotransmitter systems involved in emotional regulation. Further experiments using neurochemical and pharmacological approaches would be interesting in this model. Correspondence

In the present report changes are described in degenerating taste buds (TB) from rats deprived of the main salivary glands (parotid, sublingual and submaxillary glands). These changes include macrophages located inside the degenerating TB cell, lipid droplets and a heterogeneous population of digestive vacuoles. In addition, a large number of bacteria was found to permeate the apical taste pore. It is of interest that normal nerve fibers were seen synapsing with the degenerating TB cells. The sialectomy-induced degeneration of TB would not be, therefore, a consequence of neural deprivation.

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