Uncovering Emergent Spacetime Supersymmetry with Rydberg Atom Arrays.

In the zoo of emergent symmetries in quantum many-body physics, the previously unrealized emergent spacetime supersymmetry (SUSY) is particularly intriguing. Although it was known that spacetime SUSY could emerge at the (1+1)d tricritical Ising transition, an experimental realization is still absent. In this Letter, we propose to realize emergent spacetime SUSY using reconfigurable Rydberg atom arrays featuring two distinct sets of Rydberg excitations, tailored for implementation on dual-species platforms.

Influences of ethanol and temperature on sucrose-evoked response of gustatory neurons in the hamster solitary nucleus.

Taste-responsive neurons in the nucleus of the solitary tract (NST), the first gustatory nucleus, often respond to thermal or mechanical stimulation. Alcohol, not a typical taste modality, is a rewarding stimulus. In this study, we aimed to investigate the effects of ethanol (EtOH) and/or temperature as stimuli to the tongue on the activity of taste-responsive neurons in hamster NST.

Descending projections from the nucleus accumbens shell excite activity of taste-responsive neurons in the nucleus of the solitary tract in the hamster.

The nucleus of the solitary tract (NST) and the parabrachial nuclei (PbN) are the first and second relays in the rodent central taste pathway. A series of electrophysiological experiments revealed that spontaneous and taste-evoked activities of brain stem gustatory neurons are altered by descending input from multiple forebrain nuclei in the central taste pathway. The nucleus accumbens shell (NAcSh) is a key neural substrate of reward circuitry, but it has not been verified as a classical gustatory nucleus.

Descending projections from the nucleus accumbens shell suppress activity of taste-responsive neurons in the hamster parabrachial nuclei.

The parabrachial nuclei (PbN), the second central relay for the gustatory pathway, transfers taste information to various forebrain gustatory nuclei and to the gustatory cortex. The nucleus accumbens is one of the critical neural substrates of the reward system, and the nucleus accumbens shell region (NAcSh) is associated with feeding behavior. Taste-evoked neuronal responses of PbN neurons are modulated by descending projections from the gustatory nuclei in the forebrain.

Activation of delta-opioid receptors reduces excitatory input to putative gustatory cells within the nucleus of the solitary tract.

The rostral nucleus of the solitary tract (NST) is the first central relay in the gustatory pathway and plays a key role in processing and modulation of gustatory information. Here, we investigated the effects of opioid receptor agonists and antagonists on synaptic responses of the gustatory parabrachial nuclei (PbN)-projecting neurons in the rostral NST to electrical stimulation of the solitary tract (ST) using whole cell recordings in the hamster brain stem slices. ST-evoked excitatory postsynaptic currents (EPSCs) were significantly reduced by met-enkephalin (MetE) in a concentration-dependent fashion and this effect was eliminated by naltrexone hydrochloride, a nonselective opioid receptor antagonist.

Modulation of solitary taste neurons by electrical stimulation of the ventroposteromedial nucleus of the thalamus in the hamster.

Taste neurons in the nucleus of the solitary tract (NST) not only send axons to the parabrachial nuclei (PbN), but also receive descending projections from gustatory nuclei in the forebrain in rodents. The parvicellular portion of the ventroposteromedial nucleus of the thalamus (VPMpc) receives projections from the bilateral PbN and transmits taste information to the gustatory cortex. Here, we examined the influence of bilateral stimulation of the VPMpc on taste-responsive neurons in the NST.

Gustatory neural circuitry in the hamster brain stem.

The nucleus of the solitary tract (NST) and the parabrachial nuclei (PbN) are the first and second central relays for the taste pathway, respectively. Taste neurons in the NST project to the PbN, which further transmits taste information to the rostral taste centers. Nevertheless, details of the neural connections among the brain stem gustatory nuclei are obscure.

Modulation of activity of gustatory neurons in the hamster parabrachial nuclei by electrical stimulation of the ventroposteromedial nucleus of the thalamus.

The parvicellular part of the ventroposteromedial nucleus of the thalamus (VPMpc) is positioned at the key site between the gustatory parabrachial nuclei (PbN) and the gustatory cortex for relaying and processing gustatory information via the thalamocortical pathway. Although neuroanatomical and electrophysiological studies have provided information regarding the gustatory projection from PbN to VPMpc, the exact relationship between PbN and VPMpc, especially the efferent projection involving VPMpc to PbN, is obscure. Here we investigated the reciprocal connection between these two gustatory relays in urethane-anesthetized hamsters.

Taste-responsive neurons in the nucleus of the solitary tract receive gustatory information from both sides of the tongue in the hamster.

Taste receptors on the left and right sides of the anterior tongue are innervated by chorda tympani (CT) fibers, which carry taste information to the ipsilateral nucleus of the solitary tract (NST). Although the anterior tongue is essential for taste, patients with unilateral CT nerve damage often report no subjective change in their taste experience. The standing theory that explains the taste constancy is the "release of inhibition", which hypothesizes that within the NST there are inhibitory interactions between inputs from the CT and glossopharyngeal nerves and that the loss of taste information from the CT is compensated by a release of inhibition on the glossopharyngeal nerve input.

Efferent projection from the bed nucleus of the stria terminalis suppresses activity of taste-responsive neurons in the hamster parabrachial nuclei.

Although the reciprocal projections between the bed nucleus of the stria terminalis (BNST) and the gustatory parabrachial nuclei (PbN) have been demonstrated neuroanatomically, there is no direct evidence showing that the projections from the PbN to the BNST carry taste information or that descending inputs from the BNST to the PbN modulate the activity of PbN gustatory neurons. A recent electrophysiological study has demonstrated that the BNST exerts modulatory influence on taste neurons in the nucleus of the solitary tract (NST), suggesting that the BNST may also modulate the activity of taste neurons in the PbN. In the present study, we recorded from 117 taste-responsive neurons in the PbN and examined their responsiveness to electrical stimulation of the BNST bilaterally.

Medullary taste responses are modulated by the bed nucleus of the stria terminalis.

Previous studies have shown a modulatory influence of limbic forebrain areas, such as the central nucleus of the amygdala and lateral hypothalamus, on the activity of taste-responsive cells in the nucleus of the solitary tract (NST). The bed nucleus of the stria terminalis (BST), which receives gustatory afferent information, also sends descending axons to the NST. The present studies were designed to investigate the role of the BST in the modulation of NST gustatory activity.

Modulation of parabrachial taste neurons by electrical and chemical stimulation of the lateral hypothalamus and amygdala.

The lateral hypothalamus (LH) and the central nucleus of the amygdala (CeA) exert an influence on ingestive behavior and are reciprocally connected to gustatory and viscerosensory areas, including the nucleus of the solitary tract (NST) and the parabrachial nuclei (PbN). We investigated the effects of LH and CeA stimulation on the activity of 101 taste-responsive neurons in the hamster PbN. Eighty three of these neurons were antidromically activated by stimulation of these sites; 57 were antidromically driven by both.

Opioid modulation of taste responses in the nucleus of the solitary tract.

Gustatory processing within the medulla is modulated by a number of physiologic and experiential factors. Several neurotransmitters, including excitatory amino acids, GABA, and substance P, are involved in synaptic processing within the rostral portion of the nucleus of the solitary tract (NST). Endogenous opiates have been implicated in the regulation of feeding behavior and in taste palatability and gustatory responses in the parabrachial nuclei are reduced by systemic morphine.

Descending influences from the lateral hypothalamus and amygdala converge onto medullary taste neurons.

The lateral hypothalamus (LH) and the central nucleus of the amygdala (CeA) exert an influence on many aspects of ingestive behavior. These nuclei receive projections from several areas carrying gustatory and viscerosensory information, and send axons to these nuclei as well, including the nucleus of the solitary tract (NST). Gustatory responses of NST neurons are modulated by stimulation of the LH and the CeA, and by several physiological factors related to ingestive behavior.

Taste responses of neurons in the hamster solitary nucleus are modulated by the central nucleus of the amygdala.

Previous studies have shown a modulatory influence of forebrain gustatory areas, such as the gustatory cortex and lateral hypothalamus, on the activity of taste-responsive cells in the nucleus of the solitary tract (NST). The central nucleus of the amygdala (CeA), which receives gustatory afferent information, also exerts descending control over taste neurons in the parabrachial nuclei (PbN) of the pons. The present studies were designed to investigate the role of descending amgydaloid projections to the NST in the modulation of gustatory activity.

Taste responses of neurons of the hamster solitary nucleus are enhanced by lateral hypothalamic stimulation.

Gustatory responses in the brain stem are modifiable by several physiological factors, including blood insulin and glucose, intraduodenal lipids, gastric distension, and learning, although the neural substrates for these modulatory effects are not known. Stimulation of the lateral hypothalamus (LH) produces increases in food intake and alterations in taste preference behavior, whereas damage to this area has opposite effects. In the present study, we investigated the effects of LH stimulation on the neural activity of taste-responsive cells in the nucleus of the solitary tract (NST) of the hamster.

Gustatory projections from the nucleus of the solitary tract to the parabrachial nuclei in the hamster.

Taste-responsive cells in the nucleus of the solitary tract (NST) either project to the parabrachial nuclei (PbN) of the pons, through which taste information is transmitted to forebrain gustatory nuclei, or give rise to axons terminating locally within the medulla. Numerous anatomical studies clearly demonstrate a substantial projection from the rostral NST, where most taste-responsive cells are found, to the PbN. In contrast, previous electrophysiological studies in the rat have shown that only a small proportion (21-45%) of taste-responsive NST cells are antidromically activated from the PbN, suggesting that less than half the cells recorded from the NST are actually involved in forebrain processing of gustatory information.