Contraceptives may slow brain development and increase risk-taking behavior in teens, study suggests The HD network is often modeled as a continuous ring attractor 11, 18, 19, 20. Evidence in favor of an attractor network is plentiful, from the finding that the relative difference in preferred directions between a given pair of HD cells is maintained across different environments and during visual cue rotation experiments 21, to the finding that HD cells that fire coherently during spatial navigation continue to do so during sleep 11, to the finding that before eye-opening—when HD cell tuning curves are broad—pairs of cells exhibit similar coherence during spatial navigation as is seen in the adult HD system 22, 29, 30. Furthermore, a recent manifold analysis has validated a one-dimensional ring as a robust description of the rodent HD network 19. Our results in blind mice are consistent with those of a continuous ring attractor. Performing a manifold analysis revealed a one-dimensional ring attractor similar to that found in normally sighted animals. Additionally, upon ablating OSNs in blind animals, while this completely removed stability of HD cell preferred direction, attractor dynamics and the ring architecture remained intact.

A similar drift in HD cell preferred firing direction appears to have been described in a previous study recording from HD cells in the lateral dorsal nucleus in rats placed in the dark, though those animals were placed in a radial maze, making it difficult to draw exact parallels to our results 33. In a more recent study in mice placed in the dark, it was reported that ~40% of HD cells became unstable in the dark, with one example HD cell recording being shown where the instability resulted in the preferred firing direction exhibiting a drift similar to what we describe 34. However, a follow-up paper from the same lab showed no effect of dark exposure on HD cell stability and instead found that optogenetic silencing of the nucleus prepositus hypoglossi (NHP)—which relays vestibular signals to the HD system—was required in tandem with dark exposure to cause the preferred direction of a subset of HD cells recorded in ADn to drift over time 14. This latter study also found that preferred firing direction drift was sometimes correlated with the animal’s head turns 14. Finally, at least some portion of the drift in HD preferred firing directions that we find appears to be related to the effect described for HD cells prior to eye-opening, where the broadness of tuning curves resulted in part from an under-signaling of angular head velocity 22. Nonetheless, future work is required to better understand the circuit and synaptic basis whereby different sensory inputs enable tuning within the HD attractor network to stabilize, and how perturbations to different sensory modalities can alter the input to the HD network and result in drift. Relating head direction cell recordings in blind rodents to spatial cognition in visually impaired humans where I refers to the information content in bits/spike , P j is the probability of occupying bin j, λ j is the mean firing rate in bin j, and λ is the in-session mean firing rate of the cell. Preferred firing direction (PFD): Similar to Lozano et al. 97, PFD was defined as the angular bin with the highest normalized spike counts, whereas the mean PFD refers to the circular mean of angles. In Fig. 1e, stability was assessed based on the circular correlations of mean PFDs of exposure 1 and 2 across all recorded animals. Circular statistics were computed using the astropy module (v5.1) in Python. Intraclass correlation (ICC)To directly test whether olfactory inputs were required for stabilizing HD cell tuning in blind mice, we ablated olfactory sensory neurons (OSNs) and examined the effect on HD cell tuning. To ablate OSNs, we used a previously established chemical lesioning method 48 (see Methods). To ensure that this method was effective at ablating OSNs and severely impairing olfaction, we developed an olfactory place avoidance task in which a mouse was placed in a two-chamber arena, with one of the chambers housing an aversive olfactory substance (3-methyl-1-butanethiol 49) and the other chamber housing a neutral olfactory substance (distilled H 2O; Fig. 5b; see Methods). Mice with intact OSNs completely avoided the chamber containing the aversive olfactory substance (Fig. 5b, c). In contrast, following OSN ablation, mice showed no preference between the two chambers (Fig. 5b, c). Having established a method to reliably ablate olfaction, we tested the effect of olfactory ablation on HD cell tuning in blind animals. Olfactory ablation resulted in complete loss of HD cell tuning in ADn of blind mice (Fig. 5d, e; we pooled together rd1 and Gnat1/2 mut mice as OSN ablation affected both similarly (Supplementary Fig. 5c, d)). The percent of ADn cells that passed the criteria for being designated as HD cells drastically decreased for blind mice following olfactory ablation (Fig. 5e, Supplementary Fig. 5e, f). For some experiments, whiskers were intact during olfactory ablation, while in other animals, whiskers were ablated prior to olfactory ablation, but in both cases, olfactory ablation resulted in complete loss of HD cell tuning (Supplementary Fig. 5), again indicating that, at least in this experimental paradigm, the vibrissal system was not being used to tune HD cells. These results show that blind mice use olfactory cues to anchor their HD system.

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Best of the Web: 60 years after JFK's death it is more and more apparent that Kennedy was a victim of a palace coup - spearheaded by Vice-President Johnson Full size image The vibrissal system is not required for head direction cell tuning in blind animals in the open-field environment

Upon placing blind adult rd1 mice in the open-field environment, we found robust HD cell tuning (Fig. 1b; n = 151 HD cells recorded from 13 animals, with 80.7% of recorded cells in ADn defined as HD cells; see Methods). Similar to what has been described for sighted animals, we found that rd1 mice evenly sampled all angular directions in the environment and possessed HD cells that exhibited preferred firing directions that spanned all head directions (Fig. 1c). In my book titled Staradigm (published in 2011), I mentioned about this idea and roughly explained how it worked. It is great to finally hear that physicists of today are finding evidence that the Universe is a giant hologram. Goddess particle': Earth slammed by ultra-powerful cosmic ray, and we have no idea where it came from Here is an excerpt from my article titled How Frequency and Vibration Create Sacred Geometry and the Structures of Matter and Life that explains this process a little deeper:

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At this level, our artwork will look like flashes of electrical currents. This analogy of how a computer works is similar to how our minds and consciousness create our illusionary external reality. ... Scandalous: How the UK government shut down its Ethics Committee after it tried to intervene on the vaccination of children Next Pandemic Propaganda: The "Big One," Nipah, Ebola and Marburg, SARS1, Machupo, "Vampire Virus", Disease X

Theoretical physicist, Dr. James Gates, Jr. The idea that we live in a holographic universe that uses a form of quantum "computer code" to create the physical reality is not a new idea. In the 1940s, some physicists suggested that we live in a "computer generated" universe. In the video at the end of this article, physicists James Gates talks about this form of computer code, which he refers to as "adinkras". Full size image The olfactory system is required for stabilizing head direction cell tuning in blind animals Our results indicate that vision and olfaction can be used, either independently or in tandem, to stabilize HD cell tuning. Visual signals are believed to enter the HD system via inputs from the visual cortex to the post-subiculum and retrosplenial cortex 12. With respect to olfactory inputs, the pathway into the HD system remains unclear, though direct projections from the olfactory bulb and piriform cortex to the entorhinal cortex 54, 55 could, in turn, reach ADn via post-subiculum, which is reciprocally connected to the entorhinal cortex and ADn 56. Alternatively, olfactory signals could reach the HD system indirectly via the projection of the post-subiculum to the lateral mammillary bodies, which constitute the main subcortical input to the ADn 12. Future studies examining these pathways in more detail in both sighted and blind mice will be required to develop a better understanding of the circuitry involved. Critical concerns arise over US govt's UFO office amid uncertainty surrounding its director's future Working on a branch of physics called supersymmetry, Dr. James Gates Jr., discovered what he describes as the presence of what appear to resemble a form of computer code, called error correcting codes, embedded within, or resulting from, the equations of supersymmetry that describe fundamental particles.World's biggest iceberg starts moving for first time in decades — and it could cause some serious problems Don't mention the V word: 'Spike in strokes, cardiac arrest among young since Covid', says study in India Best of the Web: I've studied more than 5,000 near death experiences. My research has convinced me without a doubt that there's life after death SOTT Focus: MindMatters: Psychedelics, Sobriety, and Altered States: Processing Reality with John Buchanan Gates explains, " This unsuspected connection suggests that these codes may be ubiquitous in nature, and could even be embedded in the essence of reality. If this is the case, we might have something in common with the Matrix science-fiction films, which depict a world where everything human being's experience is the product of a virtual-reality-generating computer network."