the 'other' neurotransmitters

Question 1

peptides- structure

Answer 1

peptides consist of 2 or more amino acids- if the brain most peptides are NOT synthesized from smaller compounds but are the product of larger compounds- being broken down into peptides within the neuron before release at a terminal button.
- most peptides serve as modulators however many peps are known to be hormones, also act as NT and are often co released with other NT

Question 2

peptides- opioids

Answer 2

• best known family of peptide NT are endogenous opioids. in the brain the highest density of opioid receptors are in areas involved in the pain.
• endogenous opioids: ‘originating internally’ and ‘like opium’
• opiates= drugs such as morphine, heroin and opium

Question 3

heroin- opioids

Answer 3

• highly addictive- can cause death and respiratory failure.
• can destroy life without destroying brain.
• Buprenophine is a partial agonist at the receptors used as a treatment for heroin dependence
• Naloxone: full agonist and can be used to rapidly block the effect of heroin and prevent overdoes
• Methadone is also an agonist and is used in treatment od dependence because it has much slower time course than heroin. This IS used in treatment- has slower time course of heroin.
• Stops opioid for exerting its affects on synapse, so person is thrust out of their high and immediate withdrawal

Question 4

Lipids

Answer 4

• naturally occurring molecules that include fats
• they are hydrophobic= water fear
• main biological function is energy storage, signaling and provide the structural components of the cell membrane
• synthesis pathways remain unclear for many lipids serve as NT modulators.

Question 5

Lipids- Endocannabinoids

Answer 5

• • In the brain the best known lipid neurotransmitter are the endocannabinoids
  • 2 known cannabinoid receptors CB1 and CB2
  • CB1 is found in the brain and in believed to be responsible for the main psychological effects\
  • CB1 receptor activation> shortens the duration of action potentials in the presynaptic neuron> decreasing the amount of neurotransmitter released
  • By regulating the activity of those neurons and release of neuromodulators these receptors act to modulate the modulators.

Question 6

Lipids- cannabis

Answer 6

• THC is the active component of weed
• effects range from changes in appetite, time perception, arousal and have also been linked to states of apathy and underachievement

Question 7

Nucleosides- structure and synthesis

Answer 7

• nucleoside are a subunit of nucleic acids, the heredity-controlling components of all living cells- such as DNA and RNA
• usually obtained by chemical breakdown of nucleic acids
• often co transmitters that serve to modulate the release of other transmitters… again modulating the modulators.

Question 8

Nucleosdies- Adenosine

Answer 8

one example of Nucleosides is adenosine
- is a nucleoside that forms the breakdown of adenosine triphosphate (ATP)
- ATp is the primary energy source in cells for transport systems and many enzymes
- when you awake adenosine levels rise and promotes sleep and suppresses arousal
- increased firing= reduced arousal

Question 9

nucleosides- caffeine

Answer 9

• acts as adenosine-receptor antagonist and blocks natural action of adenosine
• because adenosine increases firing rate in brain areas that promote sleep, caffeine increases alertness by reducing the firing of these neurons
• very different to other true stimulant drugs like coke.

Question 10

gases- overview

Answer 10

• gas= air like fluid substance which expands freely to fill any space available, irrespective of quantity
• soluble gases= dissolve in fluid (dependent on pressure and temp)
• neurons use two gases as NT: nitric oxide and carbon monoxide

Question 11

Nitric oxide (Gases)

Answer 11

• N0 is produced from the amino acid Arginine in a subpopulation of 1-2% neurons in the cortex
• No’s exact function in the brain is unclear, it is involved in learning and memory through effects on synaptic plasticity
• it dilates blood vessels in regions of the brain that become metabolically active
  
  • No’s exact function in the brain is unclear: it is involved in learning and memory though effects on synaptic plasticity
  • It dilates blood vessels in regions of the brain that become metabolically active
    Not synthesized and stored in vesicles, it is very short lived, short life means the action will be restricted.