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Stress activates the hypothalamic-pituitary-adrenal axis through release of corticotropin releasing hormone (CRH), leading to production of glucocorticoids that down-regulate immune responses. Acute stress, however, also has proinflammatory effects that seem to be mediated through the activation of mast cells. Stress and mast cells have been implicated in the pathophysiology of various inflammatory conditions, including some in the central nervous system, such as multiple sclerosis in which disruption of the blood-brain barrier (BBB) precedes clinical symptoms. We previously showed that acute restraint stress increases rat BBB permeability to intravenous 99 Tc gluceptate and that administration of the "mast cell stabilizer" disodium cromoglycate (cromolyn) inhibits this effect. In this study, we show that the CRH-receptor antagonist Antalarmin blocks stress-induced 99 Tc extravasation, whereas site-specific injection of CRH in the paraventricular nucleus (PVN) of the hypothalamus mimics acute stress. This latter effect is blocked by pretreatment of the PVN with cromolyn; moreover, restraint stress cannot disrupt the BBB in the diencephalon and cerebellum of W/W v mast cell-deficient mice. These results demonstrate that CRH and mast cells are involved in regulating BBB permeability and, possibly, brain inflammatory disorders exacerbated by acute stress.

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The areal and laminar distribution of the cortical efferents of the medial, lateral and inferior pulvinar nuclei (PM, PL and PI respectively) were determined in rhesus monkey using autoradiography and Horseradish Peroxidase (HRP). The autoradiographic data indicated that: areas 8a, 45 and 46 on the convexity and 11 and 12 on the orbital surface of the frontal lobe received projections from PM; areas 20, 21 and 22 in temporal lobe received projections from PM primarily with caudal-medial parts of PM projecting to more rostral-dorsal parts of temporal lobe and rostral-lateral parts of PM projecting to more caudal-ventral parts of temporal lobe but PL also sends some efferents to caudal temporal lobe; areas 5 and 7 in parietal lobe and 18 and 19 in occipital lobe received projections primarily from the region in pulvinar comprising PL and PI with the more ventral parts of this region porsal parts of this region projecting to the more dorsal-lateral and medial parts of parieto-occipital cortex and with PM comtributing slightly to these projections rostrally. The autoradiographic information on the pulvinar projections to frontal lobe and temporal pole was supplemented by data derived from cortical HRP injections. These indicated that although only PM of the pulvinar subnuclei projected to these regions, three other caudal thalamic structures, i.e., medial dorsal nucleus, nucleus limitans and suprageniculate nucleus also projected to these regions raising some questions about the identity of the densocellular part of the medial dorsal nucleus which has also been considered to be part of pulvinar. The laminar distribution of pulvinar cortical efferents was uniformly similar regardless of the pulvinar recipient area examined. Elevated numbers of silver grains were observed over all cortical layers, but the silver grains were densest over the deep parts of layer III. The thalamic reticular nucleus was the only diencephalic structure observed to receive projections from pulvinar and it did so from PM, PL and PI. The pulvinar's efferents are to homotypical rather than heterotypical cortex and its connections are most extensive with cortex rather than with subcortical structures.

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The inferior parietal lobule (IPL) of the monkey is the homologous region to the supramarginal and angular gyri in man, subserving language and related cortical functions. We have examined specific zones of the IPL by injecting eight monkeys with retrogradely transported HRP, and located the positive cells in the thalamic sections with the assistance of an X-Y plotter and reference to the atlas of Olszewski ('52). Projections to the IPL were found in the following thalamic nuclei: Anterior (Anterior Medial, Anterior Ventral) ; Lateral (Ventral Anterior, Ventral Anterior magnocellularis, Ventral Lateral caudalis, Pulvinar oralis, medialis, lateralis and inferior, Lateral Posterior and Lateral Dorsal) ; Medial (Medialis Dorsalis densocellularis, parvocellularis, and multiformis) ; Midline and Intralaminar (Centralis densocellularis, Centralis lateralis, Centralis inferior, Centralis superior lateralis, Subfascicularis parvocellularis, Paracentralis and Parafascicularis) ; and Posterior (Limitans, Suprageniculatus and Geniculatus Medialis magnocellularis) .A major projection to the superior portion of the IPL was from the anterior nuclei and Paracentralis of the intralaminar group. Ventralis Lateralis and oral Pulvinar projected primarily to the anterior-inferior portion of the IPL, whereas Lateral Posterior projected most strongly to the anterior and superior portion. The major projection of the lateral Pulvinar was to the mid-superior portion of the IPL and to area 19. The projections of the inferior Pulvinar were heaviest to area 19, but there was some overlap in the mid-superior portion of the IPL with the medial and lateral Pulvinar. The major projection from the posterior thalamic nuclear complex was to the mid-IPL. The heterogeneous input from the thalamus to the IPL was not anticipated on the basis of prior anterograde or retrograde degeneration studies, and suggests that classical subdivisions of specific and associational thalamic nuclei should be revised with the axonal transport methods of study.Cerebral hemisphere connection studies have demonstrated convergence of input to certain zones in the frontal, parietal, temporal and occipital cortex (Pandya and Kuypers, '69; Jones and Powell, '70). These zones lie outside the primary receptive areas and are associative in nature. We have studied in the rhesus monkey the anatomical relationships of the clinically important representative of associational cortex, the inferior parietal lobule (IPL). This region has been designated area 7 by Brodmann ('09) and P F and PG by von Bonin and Bailey ('47). IPL lesions in humans can produce serious deficits in language, calculation, right-left and spatial orientation, figure construction, awareness of body parts and sensory stimuli, tasks involving sensory discrimination and the ability to recognize self impairment (Critchley, '53; Geschwind, '65).Microelectrode recording studies in the monkey have shown visual, auditory and sensory convergence to area 7 neurons (Hyvarinen and Poranen, '74). The subcortical rela...