Anatomical look at the olfactory tract and its relation with the thalamus

Abstract

The olfactory system is the one in charge of receiving sensory stimuli linked to the smell of substances. Its pathway begins in the bipolar Schultze cells in the olfactory mucosa and ends in the primary olfactory cortex, which includes the piriformis, amygdala, and peritonsillar cortex, and the other olfactory brain structures, including the entorhinal cortex, hippocampus, cortex. parahippocampal, thalamus, hypothalamus, orbitofrontal cortex, and insular cortex and their extension to the inferior lateral frontal region. The thalamus is a brain nucleus that fulfills a vital function of sensory regulation of the organism, intervening in a large number of mental processes that shape the way of perceiving and acting on the environment. The olfactory tract was long thought to be unrelated to the thalamus. Part of this thought came from the fact that the olfactory bulb presents its own thalamic equivalent of the same embryological derivation as this encephalic nucleus. However, the most current assertions show that the mediodorsal nucleus of the thalamus has numerous connections with the different olfactory structures that participate in the discrimination and learning of smell. Although these interactions imply a clear function of the thalamus, it is not an essential projection for this pathway. The thalamic equivalent, the interconnections of the granular and periglomerular interneurons of the olfactory bulb, accompanied by their cortical connection, are more than sufficient for the correct functioning of the olfactory pathway.