The World's Very Bizarre Adenosine Saga

(A) 100 nA microstimulation (arrow) initially evoked no effect on neuronal firing. The pipette was advanced 3 ��m and stimulation repeated. This time the stimulus evoked ... Although single�\cell microstimulation was apparently innocuous in vitro (where gentle contact between pipette and cell were closely monitored), microstimulation of spontaneously active neurons in vivo was initially associated with loss of recordings and presumed cell rupture and death. This was mitigated by withdrawal of the see more pipette from the cell once stable recordings were established such that spikes were Adenosine pulses, 0.5 s train). A similar proportion (49/74, 66%, P =0.37, Fisher's exact test) were labeled using dextran or neurobiotin in a second cohort of experiments (n = 21 rats) in which neurons in the ventrolateral medulla with respiratory�\related activity were preferentially targeted with constant�\voltage electroporation (7.5�C10 V, 200 Hz, 1 ms pulses, 0.5 s train: Fig. ?Fig.55). Single�\cell transfection in vivo Having verified that constant�\voltage electroporation is capable of reliable single�\cell transfection selleck screening library in vitro and established a protocol that results in reproducible dye�\labeling in vivo, we then examined its suitability for single�\cell transfection in vivo. Brainstem neurons were recorded 1.6�C9.8 mm deep in either nonrecovery experiments, in which urethane anesthesia was maintained for 12�C18 h after electroporation (n = 5 rats), or recovery experiments (n = 7 rats), in which anesthesia was reversed at the conclusion of recording and rats were recovered for 1�C2 days. Contact between the pipette and target neuron was first verified by observing a positive response to single�\cell microstimulation, and neurons that recovered were electroporated at negative polarity (?10 V, 50�C100 Hz, 0.5�C1 ms pulses, 1 s).