Cellular and molecular Neur

what are the two principla cell types in the nervous system

Neuron and Glia cells

The method used by Brodmann to divide the cerebral cortex into 52 discrete regions based on cellular architecture is known as___

Cytoarchitectonics

what is the role of

what are the characteristics of principle neurons

they have long axons and participate in long-range connections - typically are excitatory

what are the characteristics of interneurons

they have short axons and participate in local circuir function - typically are inhibitory

what involves a population of neurons that project from one brain region to another

a macrocircuit

what refelcts a local cell-cell interaction within a particular brain region

a microcircuit

what is the primary function of sensory neurons

to transform a specific type of stimulus (chemical, physical) into electrical signals to inform nervous system

which excitatory neurotransmitter is typically released by cortical pyramidal neurons

Glutamate and/or aspartate

what is the main distinguishing feature among different types of inhibitory interneurons

the sturcture of their axonal arbor

what is the primary role of the neuron

what is the cell membrane composed of that acts as an insulator

phospholipid bilayer

what property does the hydrophilic head of a phospholipid have

its polar and water liking

what property does the hydrophobic head of a phospholipid have

its non polar and fat liking

which organelle in the soma contains the cell’s genetic material (DNA)

the nucleus

what is the function of the nuclear envelope

its a double membrane that encloses the nucleus and isolates its contents from the cytoplasm

what is the role of ribosomes in the rough endoplsmic reticulum

assist is protein syntheis by using mRNA as a template to produce proteins

what is the function of the smooth endoplasmic reticulum

involved in lipid syntheis, calcium regulation and drug detoxification

what is the primary function od fendrites on a neuron

they are the receiving portion of the neuron, collecting electrical and biochemical signals

what are dendritic spines

protrusions on dendrites that expand their surface area and are the primary points of excitatory synaptic input

what is an action potential

an electrical signal or nerve impulse that propagates down an axon

at what part of the neuron is the action potential typically initiated

axon hillock

what are the specialised swellings at the end of an axon, which form the presynaptic part of a synapse called

terminal boutons

What is the term for the specialised connection where the communication between two neurons occurs

a synapse

what are the 6 main stages of CNS development

1. neurogenesis

2. cell migration

3. differentiation

4. synaptogenesis

5. neuronal cell death

6. synapse rearrangement

what is neurogenesis

process productiong neurons from nonneuronal progenitor cells

what is gliogenesis

process of producing glial cells from progenitor cells

which type of cells acts as a scaffold for neuronal migration during the devolpment of cerebal cortex

radial glial cells

what are the two main types of progentior cells in the developing CNS

NEPs and radial glial cells

at the end of cortical development most radial glia lose their attachement to theventriles and differentiate into ____

astrocytes

where are protoplasmic astrocytes typically found

in gray matter of the CNS

where are fibrous astrocytes typically found

in the white water of the CNS

how to astrocytes contribute to the formation of the blood brain barrier

their endfeeet wrap around blood vessles and signal endothelial cells to form tight junctions that constitute the BBB

what is the primary fucntion of myelinating glia

to form myelin sheath around axons which acts as an insulator and increases the speed of signal transmission

which type of glial cell myelinates axons in the CNS

Oligodendrocytes

which type of glial cell myelinates axons in the PNS

schwann cells

what is the key difference between Oligodendrocytes and Schwann cells regarding myelination

• an Oligodendrocytes can myelinate multiple axons and multiple internodes

• Schwann cells myelinates only a single internode on a single axon

what are the bare gaps between myelinated segments on an axon called

nodes of Ranvier

What is the primaryh role of microglial cells in the CNS

act as the main form of active immune defense capable of inflamatory and anti-inflamtory responses

what is voltage

the pressure that pushes electric charges through a conductor - a measurre of potential energy per unit charge

what is a cu

what is reistance

the property of a material that opposes or slows fown the flow of electric current

what is capitance

the ability to store an electrical charge

what does a phospholipid bilayer and a capacitor have in common

they both act as an insulator; phospholipid bilayer in cell membrane and capacitor in electrical circuit

what is Ohm’s law

states that the current (I) is equal to the voltage (V) divided by the resistance (R)

what are the requiremnets for generating cellular electrical signals like the resting membrane potential

1. a concentrartion gradient of ions across the membrane

2. selective permeability of the membrane to those ions

what is a receptor potential

a change in the membrane potential of a sensory neuron when its stimulated

which two ions have a higher concentration outsie the neuron at rest

sodium and chloride

which ion has a much higher concentration inside the neuron at rest

pottasium

what is equilibrium potential

the membrane potential at which the electrical force on an ion is equal and opposite to the chemical force from its concentration gradient resulting in no net movement of that ion

what is used to calculate the equilibrium potewntial for a single ion species

the nerst equation

The _____ equation is an extension of the Nernst equation that calculates the membrane potential based on the gradients and permeabilities of multiple ion species.

Goldman

What is the role of the Na+-K+ pump in maintaining the resting potential?

It actively transports Na+ ions out of the cell and K+ ions into the cell, against their concentration gradients, to maintain the ionic imbalance.

What is a concentration gradient?

The difference in the concentration of a substance across a space, which drives diffusion from high to low concentration.

What is a voltage gradient (or electrostatic gradient)?

A difference in electrical charge between two regions that drives the movement of ions, with opposite charges attracting and similar charges repelling.

In the context of a neuron, closed ion channels contribute to the membrane's overall _____, impeding the flow of ions.

reistance

Why do large protein anions (A-) contribute to the negative resting membrane potential?

They are manufactured inside the cell and are too large to pass through membrane channels, trapping their negative charge inside.

What is synaptogenesis?

The stage of CNS development involving the establishment of synaptic contacts as axons and dendrites grow.

The process where some synapses are lost while others are developed to refine synaptic connections is called _____.

synapse rearrangement

what ions are most critical to the electrical properties of neurons

potassium, which is positively charged; sodium, which is positively charged; and chloride, which is negatively charged.

Which type of cells in the CNS release proinflammatory factors that can disrupt blood-brain barrier integrity leading to chronic neuroinflammation and subsequent neuronal loss?

M1 Microglia

In a neuron, the conducting regions of the capacitor are represented by the intracellular and extracellular solutions. The non-conducting insulator of the capacitor is represented by what cell element?

Membrane

Active transport is primarily responsible for the uneven concentration of ____ ions inside and outside a neuron to maintain the resting potential.

sodium

The movement of ions through the brain parenchyma is a function of what cell type?

Astrocytes

When a membrane channel opens, there is a reduction in the membrane___, allowing ions to enter the neuron increasing the membrane ____, which generates ____, measured by a change in _____.

resistance, capitance, potential energy, voltage

At the resting membrane potential, the membrane is most permeable to _____, which moves __ the cell due to its voltage gradient.

potassium, into

We pass 3 amps through a membrane with a resistance of 17 ohms. What is the resulting change in potential?

51 volts

We measure the potential difference in a membrane as 20 volts and know that the membrane resistance is 5 ohms. What is the amount of current (amps) that was applied to this membrane?

4 amps

What type of glial cell is present in grey matter and has long processes that send extensions to both blood vessels and neurons?

Protoplasmic astrocytes

what is the blood brain barrier formed by

the tight junctions of astrocytes surrounding capillaries

Where do fibrous astrocytic processes contact the axonal membranes in the CNS? 

The Node

Which of the following determines the resistance to an ion's movement across a membrane?

ion channels within the membrane

What property of a material allows it to be a good conductor?

Atoms in the material have weak bonds to their electrons

With the same voltage, what is the outcome on current if the amount of resistance is doubled?

Decreases by half

if we pass 5 amps of current through a membrane and the resulting change in potential is 10 volts, what is the membrane resistance? 

2 Ohms

The resting membrane potential can be classified as a form of what kind of electricity?

static

During the remission phase of multiple sclerosis (MS), there is a resolution of inflammation, blood-brain permeability is restricted, and tissue repair is promoted. Which type of glial cell mediates this phase of the disease?

Microglia M2