PSYC2100 Mind, Brain and Behaviour Lecture Notes

1 PSYC2100 Mind, Brain and  Behaviour Dr. Hui YU ([email protected]) Week 1 Lecture 1 The Control of Movement Synapses  2 MIND, BRAIN, & BEHA...

1 PSYC2100 Mind, Brain and  Behaviour Dr. Hui YU ([email protected]) Week 1 Lecture 1 The Control of Movement Synapses  2 MIND, BRAIN, & BEHAVIOUR Welcome to Year 2 Welcome to PSYC2100 THREE elements: Biological Psychology Cognitive Psychology Research Method – quantitative  3 Lecturer: Dr. Hui YU  I will be teaching part of Biological Psychology lectures.  Office: Portland P0.37  Telephone: 0116 207 8843  Email: [email protected] (Email is the best way to reach me, but I encourage open discussions during class for the benefit of all.)  Office Hours: Available each teaching week.  Times may vary; please email me to arrange a meeting.  4  It is NOT a reductionist way What is of thinking Biological  YES all mind activities are the Psychology? product of the brain; but there is not a one-to-one map  E.g. your height is largely determined by genetic Biological Psychology is all about factors but not 100%; does anyone say “genetics study The Brain, is a reductionist way of The Story of YOU thinking”?  Experiences matter a lot; Who am I? they influence your brain What is reality? structure and function. The Who makes decisions? influence of the environment and experience work through How do I decide? your “biological” systems. …  5 What is Biological Psychology concerned? What is the biological system to support Senses? Movement? Mood? Decision? Memory?  6 Think about… What is MIND?  7 Overview of today’s lecture  The concept of the synapse  Structure of synapses  Chemical events at the synapse  Kolb, Whishaw & Teskey, Chapter 5  How to think critically  8 The gap The pros and cons of having a gap in How to “prove” the between neurons. existence of the gap?  9 The concept of synapse  Visualization: the Golgi and Cajal controversy  Observation about reflexes by Sherrington:  The speed of conduction w/ or w/o a gap should be different.  Several weak stimuli presented at slightly different times or slightly different locations produces a stronger reflex than a single stimulus does  As one set of muscles relaxes, another set becomes excited.  10 The Golgi and Cajal Controversy The Nobel Prize in Physiology or Medicine 1906, “in recognition of their work on the structure of the nervous system” Camillo Golgi Santiago Ramón y Cajal  11 Visualisation The hippocampus according to Santiago Ramόny Cajal. Notice how a circuit diagram is Drawing by Camillo drawn, Golgi of a showing hippocampus stained neurons as with the silver nitrate individual method units with information flowing Images from internet  12 Speed of conduction  Sherrington observed a difference in the speed of conduction in a reflex arc from previously measured action potentials.  He believed the difference must be accounted for by the time it took for communication between neurons.  13 Speed of conduction  14 Temporal and spatial summation  Sherrington observed that repeated stimuli over a short period of time produced a stronger response.  Sherrington also noticed that several small stimuli on a similar location produced a reflex when a single stimuli did not. 15 16  17 Temporal and spatial summation  Presynaptic neuron – the neuron that delivers the synaptic transmission  Postsynaptic neuron – the neuron that receives the message  Excitatory postsynaptic potential (EPSP) is a graded potential that decays over time and space.  The cumulative effect of EPSPs are the basis for temporal and spatial summation.  18 Excitatory and inhibitory signaling  Sherrington also noticed that during the reflex that occurred, the foot of a dog that was pinched retracted while the other three feet were extended.  He suggested that an interneuron in the spinal cord sent an excitatory message to the flexor muscles of one leg and an inhibitory message was sent to the other three legs. 19  20 The golden time is NOW Sir Charles Scott Sherrington The Nobel Prize in Physiology or Medicine 1932 (shared with Edgar Adrian), "for their discoveries regarding the functions of neurons”.  21 Chemical events at the synapse Otto Loewi The Nobel Prize in Physiology or Medicine 1936 (shared with Sir Henry Dale) "for their discoveries relating to chemical transmission of nerve impulses“. 22  23 Neurotransmitters  German physiologist Otto Loewi was the first to convincingly demonstrate that communication across the synapse occurs via chemical means.  Neurotransmitters are chemicals that travel across the synapse and allow communication between neurons.  24 Major sequence of events at the synapse 1. The neuron synthesises chemicals that serve as neurotransmitters. 2. Neurons store neurotransmitters in axon terminals or transport them there. 3. An action potential triggers the release of neurotransmitters into the synaptic cleft.  25 Major sequence of events at the synapse 4. The neurotransmitters travel across the cleft and attach to receptors on the postsynaptic neuron. 5. The neurotransmitters separate from the receptors. 6. The neurotransmitters are taken back into the presynaptic neuron, diffuse away, or are inactivated by chemicals. 7. There may be negative feedback to slow the release of further neurotransmitters. 26 The Role of Ca 2+ 27 What happens to the neurotransmitt ers left in the synapse? 28  29 Summary  How the concept of synapse was developed  The mechanism of how neurotransmitters communicate between neurons.