Spinothalamic Tracts: A bundle of NERVE FIBERS connecting each posterior horn of the spinal cord to the opposite side of the THALAMUS, carrying information about pain, temperature, and touch. It is one of two major routes by which afferent spinal NERVE FIBERS carrying sensations of somaesthesis are transmitted to the THALAMUS.Macaca fascicularis: A species of the genus MACACA which typically lives near the coast in tidal creeks and mangrove swamps primarily on the islands of the Malay peninsula.Physical Stimulation: Act of eliciting a response from a person or organism through physical contact.Posterior Thalamic Nuclei: A transitional diencephalic zone of the thalamus consisting of complex and varied cells lying caudal to the VENTRAL POSTEROLATERAL NUCLEUS, medial to the rostral part of the PULVINAR, and dorsal to the MEDIAL GENICULATE BODY. It contains the limitans, posterior, suprageniculate, and submedial nuclei.Thalamus: Paired bodies containing mostly GRAY MATTER and forming part of the lateral wall of the THIRD VENTRICLE of the brain.Stilbamidines: STILBENES with AMIDINES attached.Ventral Thalamic Nuclei: A large group of nuclei lying between the internal medullary lamina and the INTERNAL CAPSULE. It includes the ventral anterior, ventral lateral, and ventral posterior nuclei.Thalamic Nuclei: Several groups of nuclei in the thalamus that serve as the major relay centers for sensory impulses in the brain.Pruritus: An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief.Nociceptors: Peripheral AFFERENT NEURONS which are sensitive to injuries or pain, usually caused by extreme thermal exposures, mechanical forces, or other noxious stimuli. Their cell bodies reside in the DORSAL ROOT GANGLIA. Their peripheral terminals (NERVE ENDINGS) innervate target tissues and transduce noxious stimuli via axons to the CENTRAL NERVOUS SYSTEM.Capsaicin: An alkylamide found in CAPSICUM that acts at TRPV CATION CHANNELS.Evoked Potentials, Somatosensory: The electric response evoked in the CEREBRAL CORTEX by stimulation along AFFERENT PATHWAYS from PERIPHERAL NERVES to CEREBRUM.Spinal Cord: A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.Afferent Pathways: Nerve structures through which impulses are conducted from a peripheral part toward a nerve center.Posterior Horn Cells: Neurons in the SPINAL CORD DORSAL HORN whose cell bodies and processes are confined entirely to the CENTRAL NERVOUS SYSTEM. They receive collateral or direct terminations of dorsal root fibers. They send their axons either directly to ANTERIOR HORN CELLS or to the WHITE MATTER ascending and descending longitudinal fibers.Neurons: The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.Pain: An unpleasant sensation induced by noxious stimuli which are detected by NERVE ENDINGS of NOCICEPTIVE NEURONS.Evoked Potentials: Electrical responses recorded from nerve, muscle, SENSORY RECEPTOR, or area of the CENTRAL NERVOUS SYSTEM following stimulation. They range from less than a microvolt to several microvolts. The evoked potential can be auditory (EVOKED POTENTIALS, AUDITORY), somatosensory (EVOKED POTENTIALS, SOMATOSENSORY), visual (EVOKED POTENTIALS, VISUAL), or motor (EVOKED POTENTIALS, MOTOR), or other modalities that have been reported.