Cells and Membrane Potential Vocabulary

Vocabulary terms covering non-neuronal cells, nervous system disorders, and the mechanics of membrane potentials and action potentials from Problem Set 2.1.

Microglia

Non-neuronal cells that provide an immune defense in the nervous system and destroy substances that should not be there, such as amyloid protein plaques.

Astrocytes

Non-neuronal cells that regulate the exchange of materials for neurons, clear neurotransmitters like glutamate from extracellular space, and contribute to the blood supply by connecting to blood vessels.

Oligodendrocytes

Non-neuronal cells that form the myelin sheath around axons and make up the brain's white matter.

Alzheimer’s disease

A disorder characterized in part by the inability of microglia to clear amyloid protein plaques outside of neurons.

Amyotrophic lateral sclerosis (ALS)

A disorder where glutamate is not efficiently cleared from the space outside of neurons by astrocytes, leading to excitotoxicity.

Multiple sclerosis (MS)

A disorder involving a progressive loss of the myelin sheath on axons, which oligodendrocytes are unable to replace at a fast enough pace.

White matter

The part of the brain made up of tracts of axons and the myelin sheath produced by oligodendrocytes.

Resting membrane potential

The electrical potential of a neuron at rest, which is approximately $-65\,mV$. drug blocking K+ leak channels makes this value "less negative."

$Na^+/K^+$ pump

A mechanism that maintains the membrane potential by expelling $3$ $Na^+$ ions out of the cell for every $2$ $K^+$ ions it brings in.

$K^+$ leak channel

A channel open at rest that allows $K^+$ to slowly flow out of the cell.

Dendrotoxin

A drug developed by Prof. Allston that blocks voltage-gated $K^+$ channels.

Axotoxin

A drug developed by Dr. Brighton that blocks voltage-gated $Na^+$ channels with weak affinity, reducing the number of channels available to open at any given time.