from Section 2: - Anatomy
Published online by Cambridge University Press: 12 August 2022
Projection neurons are both the main target of inputs to the thalamus and the only conduit for thalamic outputs. Projection neurons show similar somatodendritic morphologies, electrotonic properties, and membrane conductances, and they are all glutamatergic. Moreover, their axons never cross the midline and always target both the prethalamic reticular nucleus and one or more forebrain structures, chiefly the cerebral cortex and/or striatum. Despite these similarities, however, new anatomical, electrophysiological, and transcriptomic methods with single-cell resolution have in recent years revealed that thalamic projection neurons are remarkably diverse. Differences prominently involve axon arborization and gene-expression patterns, but significant variations in somatodendritic morphology and membrane conductances are also evident. Here, I first review the structural, functional, and gene-expression single-cell level variation observed among thalamic projection neurons. Then, based on evidence currently available for rodents, I propose a tentative catalog of six high-level cell classes. This catalog provides a consistent and cellularly accurate framework for the analysis of classic, large-scale thalamic output pathways such as the thalamocortical, thalamostriatal, and thalamoamygdaloid, among others. Moreover, developmental studies suggest that the neuron classes identified here may reflect a fundamental level of cell-lineage diversity that precedes nuclei formation or the establishment of thalamus connection systems.
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.