1 Introduction to Neurobiology Lecture 10: The inferior olive The inferior olivary nucleus is the only source of cerebellar climbing fibers

The Inferior Olive nucleus 2 The Inferior Olive nucleus

Olivary neurons (Ramon Y Cajal) 3

HRP filled olivary neuron Intracellular labeling of olivary neuron 4

Action potential in olivary neuron 5

Action potentials in olivary neuron 6

The effect of TTX on action potentials in olivary neuron 7

8 The effect of Mn2+ and Cd2+ on action potentials in olivary neuron

Two types of action potentials in olivary neuron 9 -60 mV -55 mV -60 mV -68 mV -60 mV 15 mV 15 mV 1 nA 20 msec

The Na+ and Ca2+ components of the two types of action potentials 10

Independent activation of the action potentials 11 TTX

Refractory period of the action potentials 12 Refractory period of the action potentials

Refractory period of the action potentials 13 Refractory period of the action potentials 10 mV

The Inactivation curve of the low threshold action potential 14

The effect of Harmaline on Olivary neuron. 15 The effect of Harmaline on Olivary neuron.

The effect of harmaline on the Inactivation curve. 16 The effect of harmaline on the Inactivation curve. control harmaline Resting potential control harmaline

The effect of Octanol on Olivary neuron. 17 The effect of Octanol on Olivary neuron.

Possible mechanism of rhythmic activity 18 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

Electrical coupling between olivary neuron 19 Electrical coupling between olivary neuron Cell 1 Cell 2 20 mV Cell 1 Cell 2 5 mV 200 ms Cell 1 Cell 2 Cell 1 Cell 2 2 mV 100 ms 20 mV 200 ms 10 mV 10 mV 5

Dye coupling between olivary neuron 20 Dye coupling between olivary neuron

The olivary glumerulus 21 The olivary glumerulus

22 Olivary Gap junction