Bi-directional modulation of fast inhibitory synaptic transmission by leptin.

The hormone leptin has widespread actions in the CNS. Indeed, leptin markedly influences hippocampal excitatory synaptic transmission and synaptic plasticity. However, the effects of leptin on fast inhibitory synaptic transmission in the hippocampus have not been evaluated.

Leptin reverses long-term potentiation at hippocampal CA1 synapses.

The hormone leptin crosses the blood brain barrier and regulates numerous neuronal functions, including hippocampal synaptic plasticity. Here we show that application of leptin resulted in the reversal of long-term potentiation (LTP) at hippocampal CA1 synapses. The ability of leptin to depotentiate CA1 synapses was concentration-dependent and it displayed a distinct temporal profile.

Voltage and calcium transients in basal dendrites of the rat prefrontal cortex.

Higher cortical functions (perception, cognition, learning and memory) are in large part based on the integration of electrical and calcium signals that takes place in thin dendritic branches of neocortical pyramidal cells (synaptic integration). The mechanisms underlying the synaptic integration in thin basal dendrites are largely unexplored. We use a recently developed technique, multisite voltage-calcium imaging, to compare voltage and calcium transients from multiple locations along individual dendritic branches.

Estradiol improves cerebellar memory formation by activating estrogen receptor beta.

Learning motor skills is critical for motor abilities such as driving a car or playing piano. The speed at which we learn those skills is subject to many factors. Yet, it is not known to what extent gonadal hormones can affect the achievement of accurate movements in time and space.

A strict correlation between dendritic and somatic plateau depolarizations in the rat prefrontal cortex pyramidal neurons.

One of the fundamental problems in neurobiology is to understand the cellular mechanism for sustained neuronal activity (neuronal UP states). Prefrontal pyramidal neurons readily switch to a long-lasting depolarized state after suprathreshold stimulation of basal dendrites. Analysis of the dendritic input-output function revealed that basal dendrites operate in a somewhat binary regimen (DOWN or UP) in regard to the amplitude of the glutamate-evoked electrical signal.

The efflux of purine nucleobases and nucleosides from the rat brain.

The efflux of purine nucleobases and their nucleosides from the rat brain was investigated using the brain efflux index (BEI) method. Calculated BEI values showed that purine nucleobases had very rapid initial efflux after the intracerebral injection, which was followed by the slower efflux due to the intracellular trapping of labelled molecules and confirmed by the capillary depletion technique. The efflux of ribonucleosides was much slower than the efflux of nucleobases and the structure of the sugar moiety seemed to be important, since a significant difference in the efflux velocity between ribo- and deoxyribonucleosides was observed.