Neurotramsitters Flashcards
Acetylochline was first identified
75 years ago
This chemical is released by neurons connected to voluntary muscles causing them
To contract
ACh is formed at the what
axon terminals
How is ACh formed at the action terminals
When an action potential arrives at the nerve terminal, the electrically charged calcium ion rushes in and ACh is released ito the synapse
On voluntary muscles, this opens the sodium channels and causes
The musces to contrat
What is ACh then broken down by the enzyme
acetlocholinsesterase and resynthesized in the nerve terminal
Antibodies that block one type of receptor for ACh cause what
nyasthenia gravis a disease characterized by fatigue and muscle wekness
Recent discoveries suggest that
It may eb critical for normal attentian, membory and sleep
Amino acids
Amino acids widely distributed throughout the body and bain serve as the building blocks of proteins. Certain amino acids can also serve a neurotransmitters
What two neurotransmitters inhibit the firing of neurons
Glycine and gamma aminobutric
What is Glycine and Gamma aminobutryic acid also known as
GABA
the Activity of GABA is increased by
benzodiazepines and by anticonvulsant drugs
When dioes Huntington’s disease begin
Midlife
During Huntington’s disease what does GABA producing neurons coordinate
movement degenerate, causing uncontrollable movements
What do Glutamate and asparate act as
excitatory signlas, activating N-methyl-d-asparate NMDA receptors which have been implicated in activities ranging from learning and memory to development and specification of nerve contacts in a developing animal
the stumulation of NMDA receptors may promote beneficial changes in the brain wherease overstimulation can cause what
nerve cell damage or celld eath in trauma and stroke
Dopamine and norepinephrine are present where
in the rbain and the peripheral nervous system
the Dopamine circuit that regulates movement has been directly linked to
disease
Due to Dopamine deficits in the rbain, people wiht Parkinson’s disease show what symtoms
muscle tremores, rigidity and difficulty in moving
Parkinson’s patients can walk and do other things just by administering what
Levodopa which is a substance form which dopamine is synthesized
Another dopamine circuit is thought to be important forcognition and emotion abnormaities in this system have been implicated in schizophrenia
Because drugs that block certain dopamine receptors in the brain are helpul in diminishing psycotic symptoms, learning more about dopamine is
important to understand mental illness
In a third circuit, dopamine regulates the _system
The endocrine system
How does Dopamine regulate the endocrine system
It directs the hypothalamus to manufacture hormones and hold them in the pituary gland for release into the bloodstream of to trigger the release of hormones held within cells in the pituary
How does a neuron fire
By transmitting electrical signals along its xon. W
When signals reach the end of the axon, htey trigger the relseae of
neurotransmitters that are stored in poches that are called vesicles.. Neurotransmitters bind to receptor molecules on the surface of adjacent neurons
Nerve fibers containing norepinephrine are present throughout the brain Deficiencies in this transmitter occur in patients with what dieases
Alzheimer’s disease, Parkinson’s and korsakoffs syndrome
What does norepinephrine play a role in
learning and memory
Norepinephrine is also secreted by the what nervous system
the sympathetic
Serotonin
This neurotransmitter is present in the brain and other tissues, particularly blood patelet snad the lining of the digestive tract
In the brain, what is serotonin been associated with
sleep, mood, depression, and anxiety
Because serotin controls the differnt switches affecting various emotional states, what do scientists believe?
That these switches can be manpulated by analogs, chemicals with molecular structure similar to that of serotoin
Drugs that alter serotonin’s action such as _ relieve symtoms of depression and obsessive compulsive disorder
fluoxentine
Peptides:
Are chains of amino acids linked together
How do peptids differ from proteins
they are much larger and have more complex combination of amino acids
in 1973, receptos for opiates on neurons in several regions of the brain suggesting that
the bai must make substances very similarto opium. They found ipiate that resembled morphine
What was the morphine that is made in the brain named
It was named enkephalin meaing in the head
What is the role of opioid petids
It is unclear
A simplistic hypothesisis that they are released by th ebrain neurons in times of ) to do what
minimize pain and enhance adaptive behavior. It would explain stess related things
Opiooids and their receptos are closely associated with pathways in the brain that are activated by what
painful or tissue damagine stimuli. These signals are transmitted to teh central nervous system0 the brain and spiall cord
There are special sensory nerves that are called
C fibers that contain a peptide called substance P that causes theburn pain
What causes burning pain
Susbstance P
Trophic factors
Researchers have discovered several small proteins in the brain that are necessary fro the development, function, and survival for specific groups of neurons
The trophic factos are made where
in brain cell s and are released locally in the brain and bind to receptors expressed by specific neurons.
Researchers hav also identified fenes that code for receptos and are involved in what
The sinaling mechanisms of tropic factos
Researchers have identified genes that code for receptors and are involved in the signaling mechanizms of trophic factors/ These findings are expected to result in a greater understanding of how trophic factors work in the brain
What is a major communication system in the body
the enocrine syystem
While the nervous system uses neurotransmitters as its communication system, what does the endocrine system use?
Hormones
What are sourcs for hormones
Pancreas, kidneys, heart, adrenal glands, gonads, thyroid, parathyroid, thymus and pituary gland
The endocrine system works in large part htrough what gland
The pituary gland which secretes hormones into the blood
The endocrine system in very important for the activation and control of basic behavioral activities like
sex, emotion, and response to stress
Actions of the hormones show the brain to be vaery malleable and capable of responding t o what signla s
Environmental signals
The brain contains receptors for thyroid hormones and the six class of steroid hormones: what are they called?
androgenes, estrogens, progestins, glucorticoids, mineralocorticoids and vitamin D
Where are the receptors for the hormons found
in selected populations of neurons in the brain and relavent organs in the body
Does the brain have receptors for many Hormones?>
Yes, it does, such as metabolic hormones, and others
IN response to stress and changes in our biolgical clocks, what happnes to the hormones
they enter the lood and travel to the brain and other orgna s
In the brain, hormons alter the production of gene products that participate in what
synaptic neurotransmission as well as the structure of the brain cells
As a result of the brain keep on getting re wired, what happens?
It is constantly changing
What can severe and prolonged stress cause
prolonged brain damage
Reproduction in females is agood example of a regular cyclic process driven by circulatin hormones. What happens>
The neurons in the hypothalamus produce gondoropin-releasing hormone..which is a peptide that acts on the pituary
IN Both Males and Females the GnRH causes two hormones called
the FSH and the LH to be released into the blood tream
What are the sex hormones
Testosterone, estrogen, progestrone
The increased levels of the testosteone in males nad estrogen infemals act back on the hypothalamus to decreased the release of what>
FSH and LH The increased levels of sex hormones also induce changes in cells tructure and chemistry
What is sexual differentian of the brain caused by
sex hormones acting in fetal and early postal life.
Are there differences in the brains of men and the brains of women?
Yes, there are
Scientists identified a new class of neurotransmitters that are called what?
What are gases primarily made up of?
nutric ocide and carbon monoxide do not act like other neurotransmitters. They are not stored in anystructure, or in anything else
How do the gases act?
They diffuse into ajacent neurons and actu upon cemical targets which may be enzymes
