What is a postsynaptic neurotoxin?
What is a postsynaptic neurotoxin?
Postsynaptic neurotoxins are commonly called α-neurotoxins11,12,13, and most of these neurotoxins are from the venoms of snakes of families. Postsynaptic neurotoxins bind specially to the nicotinic acetylcholine receptor resulting in the prevention of nerve transmission, leading to death from asphyxiation14,15,16,17.
How do neurotoxins affect the synapse?
Neurotoxins inhibit neuron control over ion concentrations across the cell membrane, or communication between neurons across a synapse.
How does neurotoxic venom affect the nervous system?
Neurotoxic venom tends to act more quickly, attacking the nervous system and stopping nerve signals getting through to the muscles. This means paralysis, starting at the head, moving down the body until, if untreated, the diaphragm is paralysed and the patient can’t breathe.
What is the effect of snake venom on synapsis between neurons and muscles?
Neurotoxic snake venoms primarily affect the neuromuscular junction causing a disruption of neurotransmission, resulting in paralysis of the skeletal muscles (Harris 2009; Ranawaka 2013). Snake venom neurotoxins target multiple sites in the neuromuscular junction.
Where is the postsynaptic membrane?
the excitable membrane of the DENDRITE next to the AXON at a synapse, that receives the nerve impulse.
How do neurotoxins affect the brain?
Neurotoxins affect basic brain cell function by interfering with mitochondrial function, increasing oxidative stress, and deregulating protein turnover (3, 4).
How does neurotoxicity affect the brain?
Neurotoxicity occurs when the exposure to natural or manmade toxic substances (neurotoxicants) alters the normal activity of the nervous system. This can eventually disrupt or even kill neurons, key cells that transmit and process signals in the brain and other parts of the nervous system.
How does snake venom affect the synapse?
The toxins that block AChE are named fasciculins as they induce fasciculations of muscles due to accumulation of acetylcholine at the synapse. They bind to the peripheral site of AChE and block the entry of acetylcholine into the active site of the enzyme, thereby preventing its hydrolysis.
Does snake venom cross the blood brain barrier?
Venoms typically act quickly to immobilize prey, with non-lethal doses more slowly producing weakness and a dose-dependent range of tissue and organ toxicity. Few venoms cross the blood–brain barrier, or even gain access to the extravascular compartment environment without assisted vascular leakage.
What is the difference between presynaptic and postsynaptic?
The presynaptic neuron is the cell that sends information (i.e., transmits chemical messages). The postsynaptic neuron is the cell that receives information (i.e., receives chemical messages).
How do neurotransmitters affect the postsynaptic cell?
The binding of neurotransmitters, either directly or indirectly, causes ion channels in the postsynaptic membrane to open or close (Figure 7.1). Typically, the resulting ion fluxes change the membrane potential of the postsynaptic cell, thus mediating the transfer of information across the synapse.