Synaptic vesicles (SV) are generated by two different mechanisms, one AP-2 dependent and one AP-3 dependent. It has been uncertain, however, whether these mechanisms generate SV that differ in molecular composition. We explored this hypothesis by analyzing the targeting of ZnT3 and synaptophysin both to PC12 synaptic-like microvesicles (SLMV) as well as SV isolated from wild-type and AP-3-defic...

In response to injury, synapse alteration may occur earlier than the changes in the cell body of neurons. Although retinal ganglion cell death and thinning of the inner part of retina were found after acute high intraocular pressure (HIOP), the structural and functional changes of synapses in the retina remain unknown. In the present study, we investigated the protein and mRNA expression of syn...

Cognitive dysfunction is a common complication of diabetes mellitus however, less addressed and recognized. This study aimed to investigate the effect of type 1 and 2 diabetes on cognitive functions and related markers of hippocampal synaptic plasticity and the possible impact of blocking NMDA receptors by memantine. Seven rat groups were included in this study: Non-diabetic, non-diabeticmemant...

We explored the capacity of exercise to impact select events comprising synaptic transmission under the direction of brain-derived neurotrophic factor (BDNF), which may be central to the events by which exercise potentiates synaptic function. We used a specific immunoadhesin chimera (TrkB-IgG) that mimics the BDNF receptor, TrkB, to selectively block BDNF in the hippocampus during 3 days of vol...

Synaptotagmin is known to be a major membrane protein of synaptic vesicles (SVs) in neurons. We have now used an immunoisolation procedure to demonstrate that synaptotagmin is also present in the membranes of peptide containing large dense-core vesicles (LDCVs) of rat hypothalamus and bovine posterior pituitary. Synaptotagmin bead-immunoisolated organelles from these tissues primarily consisted...

Environmental enrichment paradigms that incorporate cognitive stimulation, exercise, and motor learning benefit memory and synaptic plasticity across the rodent lifespan. However, the contribution each individual element of the enriched environment makes to enhancing memory and synaptic plasticity has yet to be delineated. Therefore, the current study tested the effects of three of these elemen...

INTRODUCTION Cerebral ischaemia is the defining pathophysiological abnormality in most forms of vascular dementia (VAD), but the pathogenesis of the dementia remains poorly understood. In Alzheimer's disease (AD), there is early loss of synaptic proteins, but these have been little studied in VAD. MATERIALS AND METHODS We measured synaptophysin, postsynaptic density protein 95 (PSD-95), drebr...

The presence of tangles of abnormally phosphorylated tau is a characteristic of Alzheimer's disease (AD), and the loss of synapses correlates with the degree of dementia. In addition, the overexpression of interleukin-1 (IL-1) has been implicated in tangle formation in AD. As a direct test of the requirement for IL-1 in tau phosphorylation and synaptophysin expression, IL-1 actions in neuron-mi...

In rat frontal cortex, extracellular levels of glutamate are raised by the anti-psychotic drug clozapine. We have recently shown that a significant reduction in the levels of the glutamate transporter GLT-1 may be one of the mechanisms responsible for this elevation. Here we studied whether GLT-1 down-regulation induced by chronic clozapine treatment is associated with changes in the expression...

Presynaptic structural modifications are thought to accompany activity-dependent synaptic plasticity and learning. This may involve the conversion of nonfunctional synapses into active ones or the generation of entirely new synapses. Here, using an in vitro neural analog of classical conditioning, we investigated presynaptic structural changes restricted to auditory nerve synapses that convey t...