In vivo imaging of dopamine receptors in a model of temporal lobe epilepsy
Alterations in dopamine neurotransmission in animal models of epilepsies have been frequently demonstrated using invasive neuroscience or ex vivo techniques. We aimed to test whether corresponding alterations could be detected by noninvasive in vivo brain imaging with positron emission tomography (PET) in the chronic phase of the rat pilocarpine model of temporal lobe epilepsy.Six pilocarpine-treated Wistar rats exhibiting spontaneous recurrent seizures and nine control rats were studied with PET using [(18)F]-fallypride, a high-affinity dopamine D(2/3) receptor ligand. Parametric images of [(18)F]-fallypride specific binding were calculated using a reference tissue method, and the two grou…
Rapid developmental switch in the mechanisms driving early cortical columnar networks
The immature cerebral cortex self-organizes into local neuronal clusters long before it is activated by patterned sensory inputs. In the cortical anlage of newborn mammals, neurons coassemble through electrical or chemical synapses either spontaneously or by activation of transmitter-gated receptors. The neuronal network and the cellular mechanisms underlying this cortical self-organization process during early development are not completely understood. Here we show in an intact in vitro preparation of the immature mouse cerebral cortex that neurons are functionally coupled in local clusters by means of propagating network oscillations in the beta frequency range. In the newborn mouse, this…
A novel miniature telemetric system for recording EEG activity in freely moving rats
Telemetric recording systems offer the advantage to monitor physiological parameters in freely moving animals without any restrictions in their explorative behaviour. We present a novel, inexpensive, portable and reusable telemetric system to record the electroencephalogram (EEG) from adult freely moving rats under various experimental conditions. Our system consists of an implantable transmitter which communicates at a sampling rate of 500 Hz bi-directional with a receiver via radio transmission (in EU: 868.35 MHz; in USA: 916.5 MHz) over a distance of up to 3 m. The switching time between receiving and transmitting signals is 20s and the data transmission rate amounts to 115.2 kbps. The r…