Brain-wide map of projections from mice ventral subiculum

Area of Science:

• Neuroscience
• Neuroanatomy

Background:

• The hippocampal formation is vital for memory and navigation.
• The ventral subiculum (vSub) influences emotion, anxiety, and stress.
• Understanding vSub's brain connectivity is essential for its functional role.

Purpose of the Study:

• To investigate the whole-brain projections of the ventral subiculum (vSub) in mice.
• To map direct and indirect neuronal connections originating from the vSub.

Main Methods:

• Utilized a modified herpes simplex virus 1 (H129) strain with a fluorescent protein gene for viral tracing.
• Inoculated mice with the modified H129 to track neuronal transit times for primary, secondary, and tertiary projections.

Main Results:

• Identified direct vSub projections to the medial entorhinal cortex, amygdalohippocampal area, anterodorsal thalamic nucleus, medial hypothalamus, supramammillary nucleus, medial septal nucleus, diagonal band, median raphe nucleus, and interpeduncular nucleus.
• Determined that the ventral prefrontal cortex, laterodorsal tegmental nucleus, and locus coeruleus receive second-order vSub projections.

Conclusions:

• The study provides a comprehensive map of vSub projections in mice.
• These findings enhance the understanding of functional connectivity between the vSub and other brain regions involved in emotional and spatial processing.