Animal Research: Ethics, Regulations, and Neurotransmission
Animal Research: Advantages and Disadvantages
Advantages:
- Animals are simpler, more likely to reveal fundamental brain/behaviour interaction.
- Allows comparative research.
- Some experiments are not possible in humans.
Disadvantages:
- Humans are more efficient and cheaper to test.
- Animal lives should be as respected as humans.
Animal Research Regulations
Animals Act 1986: Strict regulation of all research involving vertebrates and cephalopods, no great apes. Only authorised if no other animal can be used (dogs, cats…). It is the gold standard, rolled across EU in 2013.
- Animal research should be justified according to a cost-benefit analysis that weighs the research potential advantages against any potential damage to nonhuman participants, especially important as they cannot give consent.
- All protocols must be justified, including the species used. Any changes need to be approved.
- Establishment, project, and personal licenses are required.
- Three Rs: Reduction of suffering and subjects used. Refinement of techniques to balance potential benefits and minimising harm. Replacement with non-invasive methodology should always be worked towards.
Halorw and Zimmerman (1959) monkey research on attachment.
Key Terms in Neurotransmission
Key terms: Synaptic buttons, synapse cleft, receptors, axon terminal, synaptic vesicles, neurotransmitters, pre-synaptic membrane, post-synaptic membrane, action potential.
Exocytosis: the mechanisms for neurotransmitter release.
- When the action potential reaches the synaptic buttons, the Ca2+ causes the neurotransmitters to merge with the pre-synaptic membrane, releasing their contents into the synapse.
- Once released and reaching the receptors in the post-synaptic membrane, the neurotransmitters produce signals in the neurons (EPSP/IPSP) depending on the voltage channels they activate.
- EPSP: Excitatory postsynaptic potential is the change of a postsynaptic cell’s membrane potential brought on by the entry of positively charged ions, increasing the likelihood of action potential propagation. Serves to increase excitability in neurons.
- IPSP: Inhibitory postsynaptic potential, caused by the entry of negative ions or the decrease of positive ions out of the postsynaptic cell. Represents inhibitory synapses, decreasing the likelihood of action potential propagation.
The Role of Sleep in Brain Function
Sleep has a critical role in brain function and systematic physiology, such as metabolism, appetite regulation, and the function of the immune, hormonal, and cardiovascular systems.
- Needs sufficient duration, good quality, appropriate timing, and regularity. (Medic et al 2017)
- REM is associated with emergent stage 1, characterised by rapid eye movement. Dreams occur, similar to wake EEG, vital signs are up but sleep paralysis.
- NREM: N1, transitional state between wakefulness and sleep dominated by alpha waves, lasts a few minutes. N2, deeper, brain activity slower and irregular. N3, even deeper, slow delta-waves, relaxation, and vital signs slow.
Theories of Sleep
- Restorative theories are based on the idea that sleep helps the body repair or reset. Adaptive theories suggest sleep serves some adaptive functions.
- Inactivity theory: Adaptive behaviour to protect against natural hazards/predators. (Dr. Dement, 1966) father of sleep and Kleitmann.
- Energy conservation.
- Restoration.
- Brain plasticity: Sleep can negatively or positively affect brain plasticity, impacting our cognitive function and attention. Sleep deprivation is detrimental. Babies sleep 13/14 hours a day, mostly in REM sleep – Jenkins and Dallenbach (1924).