Neural Communication Biology/Psychology 2606

Introduction It was pretty clear early on that electricity played a role of some sort in neural communication Galvani, frogs’ legs and lightning Fritsch and Hitzig stimulated cortex of various animals, got twitches Bartholow and Mary Rafferty Dr. Penfield, I smell burnt toast

EEGs are AOK Caton Helmholtz Hodgkin, Huxley and giant axons Used mircorelectrodes and oscilloscopes to measure the resting potential of a neuron -70 mV

Electrical activity of the neuron Resting potential About -70 mV Selectively allowing certain ions in With stimulation Na+ is allowed in Action potential Changes in one area lead to changes in another Chemical to electrical, very cool

The Sodium Potassium Pump Active transport takes energy Easier encoding? Faster reaction? An Action potential happens when stimulation causes the pump to sort of stop, Na gets in, K goes out Sort of reversed later

integration Excitatory postsynaptic potentials Inhibitory postsynaptic potentials Temporal summation Spatial summation

The axon Hillock Where the axon starts many voltage sensitive channels Need oh say -50 mV for depolarization Not all graded potentials are equal

Sensation and movement Receptors for Light Sound Smell Taste Touch Pain Cold heat

movement Neuron synapses onto end plate Big channels Acetylcholine Ach antagonists can cause paralysis Curare Sarin

EEG Oldest form of brain imaging

CAT Scan Computerized axial tomography

PET scan Positron emission tomography

MRI Magnetic Resonance Imaging

ERPs and single cells Event related potentials Used to see what is lit up, pretty cheap Single cell recording uses micro electrodes