I V I V

The inferior olivary nucleus is the only source of cerebellar climbing fibers

The Inferior Olive nucleus

Olivary neurons (Ramon Y Cajal)

Intracellular labeling of olivary neuron HRP filled olivary neuron

Action potential in olivary neuron

Action potentials in olivary neuron

The effect of TTX on action potentials in olivary neuron

The effect of Mn 2+ and Cd 2+ on action potentials in olivary neuron

-68 mV -60 mV -55 mV Two types of action potentials in olivary neuron 20 msec 1 nA 15 mV -60 mV

The Na + and Ca 2+ components of the two types of action potentials

TTX Independent activation of the action potentials

Refractory period of the action potentials

10 mV Refractory period of the action potentials

The Inactivation curve of the low threshold action potential

Possible mechanism of rhythmic activity Ionic currents in Olivary neurons: Na current – typical H&H current Dendritic Ca current – high threshold non-inactivating Ca dependent, K current Somatic Ca current – low threshold inactivating

Possible mechanism of rhythmic activity

Cell 1Cell 2 Cell 1 Cell 2 10 mV5 200 ms 10 mV 20 mV Cell 1 Cell 2 5 mV 200 ms Cell 1 Cell 2 2 mV 100 ms 20 mV Electrical coupling between olivary neuron

Dye coupling between olivary neuron

The olivary glumerulus

Olivary Gap junction