= Telencephalon
The \b[telencephalon] is the anterior subdivision of the embryonic <forebrain> and the corresponding territory of the mature <brain>. Its derivatives include the <cerebral hemispheres>, with <cerebral cortex>, deeper <basal ganglia> and associated structures, including the <olfactory bulbs>. It is an anatomical and developmental division, rather than a name for one behavior or one type of <neuron>.<Telencephalon in NLM MeSH>[D013687 scope note and anatomy hierarchy: anterior prosencephalic subdivision; cerebral and associated structures.]{ref}
The <forebrain> divides into <telencephalon> and <diencephalon>. These names should not be treated as interchangeable: the <thalamus> belongs to the <diencephalon>, whereas <cerebral cortex> belongs to the <telencephalon>. The large <cerebral hemispheres> can cover deeper regions in a surface view, so apparent position in a photograph alone is a poor guide to developmental membership.<Prosencephalon in NLM MeSH>[D016548 scope note: subdivision into diencephalon and telencephalon.]{ref}
A practical example is classifying structures in a section through the <brain>. A region of <cerebral cortex> and a deep <basal ganglia> nucleus can both be telencephalic even though one is superficial and the other deep. Conversely, an adjacent <thalamus> is diencephalic. This distinction makes the <telencephalon> useful as a map of related structures without assuming that everything within that map performs the same computation.
Back to article page
