The use of ultra-violet setting glue for microelectrode fabrication
Abstract The characteristics of glues which set in ultra-violet light are described with respect to their advantages for microelectrode assembly.
The electrophysiology of dopamine (D2) receptors: A study of the actions of dopamine on corticostriatal transmission
Electrophysiological recordings from the cells of the neostriatum in rats anaesthetised with halothane revealed only inhibitory actions of dopamine applied iontophoretically close to the cells. Inhibition of cortical driving seemed to have a slightly higher threshold in most cells but dopamine inhibited spontaneous action potentials, glutamate-induced responses, and cortical driving in the cells studied. Fluphenazine applied iontophoretically blocked the actions of dopamine but was itself without effect on the neuronal responses. Sulpiride, in contrast, was without effect on the spontaneous activity of the cells and was ineffective in blocking the action of applied dopamine. Sulpiride, nevertheless, increased the response to cortical stimulation though it had no action on the response to applied glutamate. These results suggest that the sub-class of dopamine receptors on the terminals of the corticostriatal pathway may be inhibitory on glutamate release and preferentially sensitive to blockade by sulpiride.
The nature of action potentials in the lateral eye of the horseshoe crab as revealed by simultaneous intra- and extracellular recording.
1. By means of pencil electrode, simultaneous intra-and extracellular recordings were made of the action potentials in the lateral eye of the horseshoe crab (Tachy_pleus tridentatus). A method of compensation was combined to minimize the capacitive coupling between the inner and outer pipette of the pencil electrode and also to reduce the effective input capacitance of each pipette.2. The obtained result confirmed the conclusion in a separate paper (12) that the ommatidial action potential has its origin a little distance from the site of impulse generation. Discussion was made more about the mechanism.3. The membrane resistance of photosensitive cells within ommatidia was found to re-increase during illumination in the wake of sudden decrease at the onset of illumination, providing an explanation of the fact that the off-deflection far smaller than the on-deflection in the extracellularly recorded ommatidial action potential.4. The light adaptation affected much the height of initial peak of the ommatidial action potential, but its effect on the following steady level of depolarization was small.5. Occasionally, the membrane was inflicted a local inactivation by the tip of microelectrode.