Someone recently bought our

students are currently browsing our notes.

X

Intro To Biological Psych Notes

Psychology Notes > Intro to Biological and Cognitive Psych (1st year) Notes

This is an extract of our Intro To Biological Psych document, which we sell as part of our Intro to Biological and Cognitive Psych (1st year) Notes collection written by the top tier of Durham University students.

The following is a more accessble plain text extract of the PDF sample above, taken from our Intro to Biological and Cognitive Psych (1st year) Notes. Due to the challenges of extracting text from PDFs, it will have odd formatting:

Biological Psych
How are memories stored?
Repetition  memory  'Use it or lose it'Use it or lose it'
Action Potential = electric signal conducted along the axon  synapse
Inside/outside neuron = different voltage  electric gradient
Resting Potential
 Na+ and K+ AT out of axon by Na+/K+ pump
 AT of Na+ > K+ 3:2 ∴ pd across membrane
 Most Na+ gates shut / K+ gates open
 Axon membrane 100x more permeable to K+ which diffuse out
 Further ↑ pd
 Axon -ve due to K+ > Na+ -70mV
 Outside +ve due to Na+ > K+

Action Potential
= temporary wave of depolarisation  Domino effect







At RP inside = -70mV - some K+ channels are open, all Na+ ch close
E of stimulus causes some K+ ch to close and Na+ ch to open
Na+ diffuses into axon and starts an AP
+ve feedback Na+ -membrane depolarises
When action potential reaches +40mV - Na+ close, K+ opens
+ve feedback K+- membrane repolarises - reverses electrical gradient
Chemical pump reverses ion balance by moving Na+ out and K+ in to generate another AP
AP only occur when a threshold is met: all or none principle

Critical properties of AP:
 All or none
 AP do not vary in strength
 Slow speed
 Takes time to recover  max FR = 150Hz
What starts an AP?
 Sensory receptors
 Environmental change
 Chemical signalling from nearby neurons
How does an organism perceive stimuli?

1. Number impulses in a given time

2. Neurons with different thresholds  which neurons and how frequent = interpret strength
Refractory Period  return back to normal voltage - Na+ closed Biological Psych


Ensures AP in only 1 direction
Ensures AP are separated
Limits number of AP

AP = needs oxygen and E from blood
 AP measured as blood flow/oxyHb/gl levels
PET = uses radioactive markers

measure blood flow and glucose levels fMRI = changes in O2 and OxyHb levels
Spatial resolution = how closely recordings tell you how neurons are firing
Temporal resolution = how well you can determine when the activity happened
Hyper-polarisation
 Overshoot K+ moving out of axon
 Axon inside = -ve
 K+ close
 Refractory period
Saltatory conduction = conduction passes down myelinated axon and jumps from 1 Node of Ranvier to the next
Depolarise = excite -70mV +40mV
EPSP = excitatory  increase chance AP - depolarise neuron
IPSP = inhibitory  decrease chance AP - hyperpolarise neuron
IPSPs can spread and counteract EPSPs
Summation = SUM of many voltage changes exceeds threshold
Spatial Summation = many presynaptic neurons together releases enough NT to exceed threshold
Temporal Summation = single pre-synaptic neurons together release enough T to exceed threshold
Recording AP - v fine in membrane or coarse electrode in extracellular space
EEG = multi-electrode - record times from 1 part of brain to another
Extracellular Unit Recording = record electrical disturbance created each time an adjacent neuron fires
Intracellular Unit Recording = record membrane potential form 1 neuron as it fires
Recording EPSPs/IPSPs: large electrode inside and on surface of cortex and scalp
Measured EEG activity = combined IPSPs/EPSPs in 1000s cells
Brain stimulation Biological Psych
Can induce AP by creating voltage difference with electrodes
Intracellular  AP
Extracellular  EPSPs
Synaptic transmission
AP down axon
 release of NT from vesicles
NT  synapse  binds with receptor sites  AP
NT cleared out by:
 Reuptake
 Enzyme break down in synapse
 Binds to auto receptors
NT

Glial cell

Cell body
Synapse
Interneurons
Purkinje cells
Pyramidal cells
Bipolar cells
Terminal bouton

Chemicals that transmit info  synapse to next neuron
Released when membrane depolairses due to AP
Allows Ca2+  axon terminal
Physically support neurons  supply nutrients and increase neural communication 85 billion
Info-processing tasks
Protein synthesis, E prod, metabolism
Junction between axons 100-500 trillion
Connects sensory/motor neurons
Interneurons carrying info from cerebellum  rest of brain/spinal cord
Triangular cell bodies and single long dendrite among small ones
Sensory neurons in eye retina with single axon and a few dendrites
Bulbous - NT released

Vesicle fuse with axon terminal on cell membrane
Releases NT  synaptic cleft
NT binds with receptors  changes electrical permeability
Each NT has its own receptor
Ach

Regulates motor control
 attention, learning, memory, sleep
Mvt, motivation, arousal, pleasure
Learning and memory
Primary inhibitory NT
Mood and arousal
Hunger, sleep, arousal, aggression
Pain and emotion

Dopamine
Glutamate
GABA
Noradrenaline
Serotonin
Endorphins
Drug Action:
Agonists = increase NT action
Antagonists = decrease NT action

Buy the full version of these notes or essay plans and more in our Intro to Biological and Cognitive Psych (1st year) Notes.