Tryptophan Improves Memory Independent of Its Role as a Serotonin Precursor: Potential Involvement of Microtubule Proteins.

There are numerous studies examining the effects of tryptophan on behavioral processes, including learning and memory. While most studies suggest that fluctuations in tryptophan levels exert their effects through modifications in serotonergic neurotransmission, there are other neural mechanisms that have accounted for the observed outcomes as well. In this study, we demonstrated that acute administration of tryptophan modulates spatial and object-recognition memory independent of its role as a serotonin precursor. One possible explanation for the observed improvement in memory is through the interaction between tryptophan and microtubule proteins. Microtubules are key components involved in the morphological and functional development of neurons. Moreover, several models suggest that microtubule dynamics contributes to neural network connectivity, information processing, and memory storage. Here, we examined the interaction between tryptophan and microtubules and indicated that tryptophan is capable of a creating a static interaction with the tubulin dimer through a single binding site. This interaction induces the rate of tubulin assembly and as a result increases polymer mass.

Variations of glutamate concentration within synaptic cleft in the presence of electromagnetic fields: an artificial neural networks study.

Glutamate is an excitatory neurotransmitter that is released by the majority of central nervous system synapses and is involved in developmental processes, cognitive functions, learning and memory. Excessive elevated concentrations of Glu in synaptic cleft results in neural cell apoptosis which is called excitotoxicity causing neurodegenerative diseases. Hence, we investigated the possibility of extremely low frequency electromagnetic fields (ELF-EMF) as a risk factor which is able to change Glu concentration in synaptic clef. Synaptosomes as a model of nervous terminal were exposed to ELF-EMF for 15-55 min in flux intensity range from 0.1 to 2 mT and frequency range from 50 to 230 Hz. Finally, all raw data by INForm v4.02 software as an artificial neural network program was analyzed to predict the effect of whole mentioned range spectra. The results showed the tolerance of all effects between the ranges from -35 to +40 % compared to normal state when glutamatergic systems exposed to ELF-EMF. It indicates that glutamatergic system attempts to compensate environmental changes though release or reuptake in order to keep the system safe. Regarding to the wide range of ELF-EMF acquired in this study, the obtained outcomes have potential for developing treatments based on ELF-EMF for some neurological diseases; however, in vivo experiments on the cross linking responses between glutamatergic and cholinergic systems in the presence of ELF-EMF would be needed.