block 2-cores of neurobiology Flashcards
(21 cards)
brains
brains are networks of neurones
-neurones= functional units of neuronal processing e.g. building blocks of nerves
-the network of neurones is organised to provide logical solutions to practical problems
-organs that generate behaviour
nervous system diversity
-different animals have different numbers of neurones in their nervous system
-the number of neurones in the nervous system provides a very crude measure of complexity
-neurones in vertebrates and invertebrates share many common features but also have some differences
what is a neuron
-specialised cells in the nervous system
-connect to each other at synapses
other than neurones that make up the nervous system
-glial cells= form myelin sheath
-muscle cells= electrically excitable and get inputs from motor neurones to generate movement
-sensory neurons = turn the sensory inputs into signals
classifying neurones
-Function e.g. sensory and motor
-morphology e.g. shape,location, branching regions
how do we study the nervous system
- physiologically= electrical recordings
-staining neurones
-anatomically = looking at the structures of a neurone
how do neurones signal within the nerve cells?
- they code and process information by generating, transmitting and receiving two types of chemical signals : electrical and chemical
-signals within nerves= electrically
-signals between nerve cells can be either electrical or chemical
how can the resting potential within a nerve cell be recorded?
-by placing a microelectrode into the cell cytoplasm
electrical signals
- transmits information by travelling along the dendrites and axons of neurons
-code information in 2 ways: action potentials and graded responses passively propagating, decrementing changes in membrane potential
-rapid
terms to describe firing patterns
-phasic= fires a short burst of action potentials
-Tonic= fires action potentials more or less constantly
-endogenous burster= neurones that repeatedly fire short bursts of action potentials
presynaptic
-upstream neuron
postsynaptic
downstream receiving neuron
EPSP= excitatory postsynaptic potential
-synaptic potential with reversal potential negative to the spike threshold potential
IPSP= inhibitory postsynaptic potentials
-synaptic potentials with a reversal potential negative to the spike threshold potential
properties of chemical synapses
-summation: temporal and spatial. happens at the postsynaptic cell
-facilitation = synapses get stronger each action potential causes a bigger affect in the next one
-depression= epsp gets small after each action potential
neurotransmitters
released at chemical synapse with direct effects on the postsynaptic cell
neuromodulator
released from a neuron in the vicinity of a target cell. no direct synaptic contact
neurohormone
released from a neuron into the blood circulation, to act on a distant target
electrical synapses
- do not use neurotransmitters but instead allow electrical signals to pass directly between cells
-very rapid and found where speed is important
structure of electrical synapses-BIGGER FISH TO FRY. MAYBE CHEAT SHEET
formed by protein channels called connexons. These connexons bridge the small gap between adjacent cells, creating a continuous cytoplasmic connection that enables ions and small molecules to pass freely. This direct coupling allows electrical signals to travel bidirectionally or unidirectionally with minimal delay, making electrical synapses ideal for synchronizing neuronal activity, such as in reflex circuits or in certain regions of the brain.
properties of neuronal networks-IDK RN MAYBE CHEAT SHEET
- give rise to ‘emergent properties’ such as: oscillations and population coding
-can change over time = synaptic strengths can change or be turned off and no. can effectively add or remove neurons from the circuit in different situations
-can share neurons
