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Biology of the Mind Neural and Hormonal Systems Worth/Palgrave/Macmillan Publishers. Chapter Objectives. To be familiar with the different parts of a neuron, as well as it types and functions. To be able to trace how neurons communicate with one another.
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Neural and Hormonal Systems
To be familiar with the different parts of a neuron, as well as it types and functions.
To be able to trace how neurons communicate with one another.
To be familiar with different parts of the nervous system and their functions
To identify parts of the endocrine system and their influence in human behavior
To be familiar with Neurotransmitters, neuromodulators, endorphins, and hormones and their function(s).
To be familiar with the different ways of measuring brain activity.
This depolarization produces another action potential farther along the axon. Gates in the neighboring area open, and move positively charged ions in, while the positively charged ions in the previous sections of the axon exit.
Cell body end
Direction of neural impulse: toward axon terminals
The ultimate effect is either:
Excitatory: the probability that the receiving neuron will fire increases
Inhibitory: the probability that the receiving neuron will fire decreasesNeurotransmitters
Most endorphins act as neuromodulators, which alter the effect of neurotransmitters by limiting or prolonging their effects.
**Neuromodulators are chemicals released by neurons in larger amounts and diffused for the longer distances, modulating the activity of many neurons in a particular part of the brain.
**Many neurons contain hormone receptors, thus influencing their activity.
Morphine mimics the action of neurotransmitters by stimulating receptors in the brain involved in mood and pain sensation.
The antagonist molecule inhibits by blocking the neurotransmitters or by diminishing their release.
Botulin poison causes paralysis by blocking receptors for acetylcholine (a neurotransmitter that produces muscle movement)How Drugs and Other Chemicals Alter Neurotransmitters
Agonists excite: Morphine mimics the action of endorphins
Receptor site on
Antagonists inhibit: Botulin (botox) paralyses muscle
Decrease in norepinephrine and serotonin is associated with depression. Elevated levels along with other biochemical and brain abnormalities have been implicated in childhood autism.
Norepinephrine, epinephrine, and adrenaline are associated with excitement and stress.Neurotransmitters & Hormones
Cortisol is associated with stress. Increase in cortisol damages the brain and may be associated with posttraumatic stress.
Abnormal GABA levels have between implicated in sleep and eating disorders and in compulsive disorders.
Glutamate, serotonin, and high levels of dopamine have been associated with schizophreniaNeurotransmitters & Hormones
Can damaged neurons in the central nervous system multiply and grow back?
to the Neuroaxis
(Cranial and Spinal nerves)
self-regulated action of
internal organs and glands)
voluntary movements of
***(Cortisol; Epinephrine; Adrenolin)
This signal that is picked up by each electrode is then amplified, stored and displayed on a monitor. We also measure several other physiological signals in conjunction with the EEG such as the ECG (heart function), respiration (lung function) and EMG (muscle function), as these recordings can influence the EEG.
We then analyse the EEG by visual inspection to assist in the diagnosis and prognosis of the newborn. Our analysis usually involves locating abnormal EEG in a recording. The normal EEG appears to be a random signal without any obvious pattern. The EEG becomes abnormal when certain patterns appear in the EEG and it loses the underlying randomness of a normal recording. The normal EEG pattern and several abnormal EEG patterns are shown in this figure .
• CAT (or CT) scans use an X-ray source
that is moved around the head by steps.
• Detectors on the opposite side detect the
amount of radiation that is absorbed.
• This measures the density of brain
• More detailed than CAT scans.
• The head is placed into a powerful magnetic field
(strong enough to lift a car!).
This aligns all the brain’s protons in one
• The protons are then knocked over by a powerful
pulse of radio waves (loud!).
• The pulse is turned off and protons relax back to
their original position, giving off radio waves.
• Detectors around the head detect those waves.of radiation that is absorbed.
• This measures the density of brain
with incipient Alzheime’s
Disease: Notable neural atrophy of the right hemisphere
• Measures activity, not structure.
• A radioactive form of glucose is injected into the bloodstream.
• A ring of detectors maps the location of the radioactivity, as the glucose is taken up for energy.
• Subject may perform a task.
• Color is used to distinguish different levels of radioactive emissions.
• Similar to regular MRI, except that high-powered, rapidly alternating magnetic fields are used to detect small changes in oxygen use.
• Good spatial and temporal resolution
Further reading on neonatal EEG can be found in,
G.B. Boylan, "Principles of EEG and CFM" in Neonatal Cerebral Investigation, Chapter 2, Eds: J.M. Rennie, Robertson and Hagmann. Cambridge University Press, UK, 2008.
G.B. Boylan, J.M. Rennie, and D.M. Murray. "The normal neonatal EEG" in Neonatal Cerebral Investigation, Chapter 6, Eds: J.M. Rennie, N.J. Robertson and C.F. Hagmann. Cambridge University Press, UK, 2008.
G.B. Boylan, "Neurophysiology in the Neonatal Period", in Neonatal and Paediatric Clinical Neurophysiology, Eds: R.M. Pressler, C.D. Binnie, R. Cooper and R. Robinson, Churchill Livingstone Elsevier, The Netherlands, 2007