Supplementary Materials1. provides amplification and enhanced precision of the head-direction signal.

Supplementary Materials1. provides amplification and enhanced precision of the head-direction signal. Introduction The relationship between stimulus-driven and internally generated activity is a recurring topic in neuroscience. Yet, how feed-forward sensory signals in subcortical, thalamic and cortical networks interact with internally organized (self-generated or spontaneous) activity is not well-understood, due largely to the high dimensionality of sensory signal order GDC-0941 attributes1C4. In contrast, the one-dimensional head-direction (HD) sense offers an opportunity to explore such interactions experimentally. HD neurons fire robustly when the animals head points in a specific direction5C8. The HD system encompasses multiple, serially-connected brain networks, including the brainstem, mammillary bodies, anterodorsal thalamic nucleus (ADn), post-subiculum (PoS) and entorhinal cortex6C13. Neurons in the PoS provide feedback projections to neurons in the mammillary and ADn physiques7. Similar to additional sensory systems that go through the thalamus, the HD feeling order GDC-0941 continues to be assumed to become mainly managed by peripheral inputs tacitly, the vestibular and ancillary afferents7 primarily,8, since firing prices of HD cells are affected both by mind direction as well as the angular speed of mind rotation in the discovering rodent9,14. Visible inputs can impact the HD sign6 also,9,10 via reciprocal contacts from the PoS with visible areas7,8 but visible inputs aren’t sufficient to operate a vehicle HD cells in the PoS after lesioning the ADn14. The HD network can be a key area of the brains navigational program and HD info is thought to be crucial for the introduction of grid cells in the entorhinal cortex12,13,15C17. Computational versions possess assumed that HD cells with identical preferred directions open fire together as well as the temporally correlated band of HD neurons (known as activity packet) progresses a virtual band as the pet turns its mind (Film 1). While people of the experience packet rotate for the band, neighboring neurons are suppressed by lateral inhibition18C23. Experimental demo from the lifestyle of structured neuronal populations endowed with such properties order GDC-0941 internally, also known as attractor systems 22,24C26, requires monitoring populations of HD neurons simultaneously and demonstrating that the activity packet remains temporally organized even in the absence of vestibular and other peripheral signals. We therefore reasoned that the postulated attractor dynamic can be revealed by comparing the population activity of HD cells during sleep and in the waking brain27,28. Results Ensembles of HD neurons from ADn (8.4 5.1 s.d. units per session) and PoS (5 2.8 s.d.) were recorded by multi-site silicon probes (Fig. 1a, Supplementary Fig. 1) in 7 mice foraging for food in an open environment (42 sessions) and in their home cages during sleep (Supplementary Table 1). In 3 mice (21 sessions) ADn order GDC-0941 and PoS recordings were performed simultaneously. HD cell ensembles covered the full span of head-directions (Fig. 1bCd). ADn and HD cells were characterized by a uniform bell-shaped tuning curve (Fig. 1b; Supplementary Fig. 2a). ADn neurons exhibited peak rates almost three times higher than PoS cells (Supplementary Fig. 2b; p 10C10, Mann-Whitney U-test, n = 242 ADn and n = 111 PoS HD cells) and conveyed 30% more head-direction information than PoS cells (1.44 bit per spike vs. 1.11 bit per spike; see Methods; Supplementary Fig. 2c; p 10C6, Mann-Whitney U-test), firing more consistently with the head-direction. Open in a separate KIAA0937 window Figure 1 Persistence of information content during wake and sleep in the thalamo-cortical HD circuita: Dual site saving of cell ensembles in the Antero-Dorsal nucleus from the thalamus (ADn) as well order GDC-0941 as the post-subiculum (PoS). 4,6-Diamidino-2-Phenylindole (DAPI) staining of the coronal section through the PoS (best; arrowheads indicate paths) and ADn (bottom level; DAPI coupled with parvalbumin yellow.