Prevention of Lipotoxicity in Pancreatic Islets with Gammahydroxybutyrate.

Oxidative stress caused by the exposure of pancreatic ß-cells to high levels of fatty acids impairs insulin secretion. This lipotoxicity is thought to play an important role in ß-cell failure in type 2 diabetes and can be prevented by antioxidants. Gamma-hydroxybutyrate (GHB), an endogenous antioxidant and energy source, has previously been shown to protect mice from streptozotocin and alloxan-induced diabetes; both compounds are generators of oxidative stress and yield models of type-1 diabetes.

Early-Age Running Enhances Activity of Adult-Born Dentate Granule Neurons Following Learning in Rats.

Cognitive reserve, the brain's capacity to draw on enriching experiences during youth, is believed to protect against memory loss associated with a decline in hippocampal function, as seen in normal aging and neurodegenerative disease. Adult neurogenesis has been suggested as a specific mechanism involved in cognitive (or neurogenic) reserve. The first objective of this study was to compare learning-related neuronal activity in adult-born versus developmentally born hippocampal neurons in juvenile male rats that had engaged in extensive running activity during early development or reared in a standard laboratory environment.

Organotypic slice cultures for studies of postnatal neurogenesis.

Here we describe a technique for studying hippocampal postnatal neurogenesis in the rodent brain using the organotypic slice culture technique. This method maintains the characteristic topographical morphology of the hippocampus while allowing direct application of pharmacological agents to the developing hippocampal dentate gyrus. Additionally, slice cultures can be maintained for up to 4 weeks and thus, allow one to study the maturation process of newborn granule neurons.

Homeostatic regulation of adult hippocampal neurogenesis in aging rats: long-term effects of early exercise.

Adult neurogenesis is highly responsive to environmental and physiological factors. The majority of studies to date have examined short-term consequences of enhancing or blocking neurogenesis but long-term changes remain less well understood. Current evidence for age-related declines in neurogenesis warrant further investigation into these long-term changes.

Enhanced post-ischemic neurogenesis in aging rats.

Hippocampal neurogenesis persists in adult mammals, but its rate declines dramatically with age. Evidence indicates that experimentally-reduced levels of neurogenesis (e.g.

Biphasic effects of the cholinergic agonist carbachol on long-term potentiation in the dentate gyrus of the mammalian hippocampus.

The dentate gyrus, an integral part of the hippocampal circuit, is capable of producing new neurons in adulthood, some of which become integrated into neuronal circuits that participate in processes underlying learning and memory. Acetylcholine (Ach) is an important neuromodulator of synaptic activity in the hippocampus but its action on activity-dependent plasticity of mature and young neurons has not been studied. Using standard hippocampal slice preparations and a functional assay for distinguishing young and mature neuronal populations, we found that Ach has a preferential stimulatory effect on long-term synaptic plasticity of mature neurons.

The site of a motor memory shifts with consolidation.

The basis for the consolidation of memory is a controversial topic, particularly in the case of motor memory. One view is that motor memory is transferred, partially or completely, to a new location during the consolidation process ("systems consolidation"). We investigated this possibility in a primitive motor system, the vestibulo-ocular reflex (VOR).

Asymmetric responses to rotation at high frequencies in central vestibular neurons of the alert cat.

The horizontal rotatory vestibulo-ocular reflex (VOR) stabilizes gaze by moving the eyes at an angular velocity proportional to head velocity, and can accomplish this for a broad range of frequencies and amplitudes of head motion. Rotation at 5 Hz and above may be processed differently than lower frequencies by the VOR network. We recorded discharges and calculated spike densities of a small sample of vestibular neurons in alert cats during low-velocity rotation at frequencies up to 8 Hz.

Influence of NO downregulation on oscillatory evoked responses in developing rat superior colliculus.

Nitric oxide (NO) is involved in neuronal transmission by modulating neurotransmitter release in adults and in stabilizing synaptic connections in developing brains. We investigated the influence of downregulation of NO synthesis on oscillatory components of ON and OFF evoked field potentials in the rat superior colliculus. NO synthesis was decreased by inhibiting nitric oxide synthase (NOS) with an acute microinjection of N(omega)-nitro-L-arginine methyl ester (L-NAME).