Week 1: neural reading part 2

Week 1: neural reading part 2

1. EEG = 2 types of activity recorded from nervous tissue 1) electromagnetic activity. 2) metabolic-related activity

   • generating APs and transmitting signals = electromagnetic. energy = metabolic
     • electroencephalography = record small variations in electrical potential. will record the differences in electrical potential between 2 electrodes.
       • temporal resolution = GOOD. spatial resolution =BAD, impossible to tell the exact area

2. about 600 skeletal muscles in human body attached by connective tissue. skeletal muscles made from muscle fibres.

   • muscle connected to bone by collagen rich connective tissue = tendon
     • muscle fibres are innervated by motor neurons. chemical synpases = neuromuscular junctions, ACh released in terminals
       • single action potential = sufficient to evoke AP in muscle fibre.

3. 3 types of motor neuron: alpha = only extrafusal. beta = innverate extrafusal and intrafusal. gamma = only intrafusal

   • extrafusal = main fibres of the muscle. intrafusal = spindle fibres
     • CONGENTRIC CONTRACTION = decrease in length. EGGCENTRIC CONTRACTION = increase in length. ISOMETRIC CONTRACTION = no change in length

4. single AP - twitch contraction, train of AP - tetanic contraction.

   • = fused, any further AP will not lead to an increase in force.
   • Alpha motor neuron + the muscle fibres it innervates = MOTOR UNIT.
   • small motor units tend to be activated before larger ones.

5. the more active motor units = greater muscle force.

   • EMG = invasive to record specific muscle activity. connected to an amplifier to record the activity.

6. motor planning

7. minimum jerk model = Flash and Hogan 1985

   • minimum torque model = Uno et al. 1989
     • minimum variance model = Harris and Wolpert 1998

8. human brain 100 billion neurons

9. depolarisation = MORE POS/EXCITATION, hyperpolarisation = MORE NEG./INHIBITORY

   • INFLUX OF CALCIUM CAUSES RELEASE OF VESICLE (NEUROTRANSMITTER), GENERATES POST SYNAPTIC POTENTIALS

10. Electrical discharge of large populations of neurons = EEG/MEG, chemical changes PET, single muscles = EMG

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