Extracellular glutamate accumulates only in final, ischemic stage of progressive epidural mass lesion in cats

Epidural mass lesions may cause ischemia due to progressive intracranial hypertension. In order to 1) investigate the impact of intracranial pressure (ICP) on accumulation of neuroactive substances, and 2) test the significance of neurochemical monitoring for early prediction of fatal outcome, we gradually raised ICP in cats by inflation of an epidural balloon: We assessed extracellular substrate alterations in the contralateral cortex in relation to changes of ICP, cerebral perfusion pressure (CPP) and mean arterial blood pressure (MABP). In a complementary experiment, regional cerebral blood flow was assessed by sequential positron emission tomography (PET).peer-reviewe

Deficient neuron-microglia signaling results in impaired functional brain connectivity and social behavior

Microglia are phagocytic cells that infiltrate the brain during development and have a role in the elimination of synapses during brain maturation. Changes in microglial morphology and gene expression have been associated with neurodevelopmental disorders. However, it remains unknown whether these changes are a primary cause or a secondary consequence of neuronal deficits. Here we tested whether a primary deficit in microglia was sufficient to induce some autism-related behavioral and functional connectivity deficits. Mice lacking the chemokine receptor Cx3cr1 exhibit a transient reduction of microglia during the early postnatal period and a consequent deficit in synaptic pruning. We show that deficient synaptic pruning is associated with weak synaptic transmission, decreased functional brain connectivity, deficits in social interaction and increased repetitive-behavior phenotypes that have been previously associated with autism and other neurodevelopmental and neuropsychiatric disorders. These findings open the possibility that disruptions in microglia-mediated synaptic pruning could contribute to neurodevelopmental and neuropsychiatric disorders