Thoughts on week 4


In this week’s lecture we talked about neurotransmitter systems. We concentrated a lot on the difference between ionotropic and metabotropic receptors. It seems that most neurotransmitters effect ion channels and G-protein related cascades. The transmitters that activate ion channels in a direct manner, like glutamate, GABA and acetylcholine, can have faster effects than transmitters that activate ion channels through metabotropic receptors. The metabotropic receptors can also have faster and slower activation patterns. The faster one’s activate an ion channel through conformation change in the G-protein and slower ones modulate the cell’s activity through signalling cascades that involve conformation change in the G-protein and phosphorylation of second messengers. The cascades can lead to diverse effects in the cell, eg. release of Ca2+ from internal storage, opening of different ion channels and gene transcription.

I had been wondering if G-protein coupled receptors are synonymous to metabotropic receptors and according to the lecture it seems that G-protein receptors are the only known metabotropic receptors. But this may change as the research develops. I think it can be quite likely that different kinds of metabotropic receptors can be found since the animal cells capacity for diversity seems huge.

What was especially interesting for me was the detail about negative correlation between mu opioid receptor density in certain brain areas like amygdala and thalamus and anxious and avoidant attachment styles in humans. It might implicate that the psychological pain response is greater in subjects with mentioned attachment styles. It would be interesting to know if there is correlation between the stress system’s programming and the attachment styles.