Microstimulation in Different Parts of the Periaqueductal Gray Generates Different Types of Vocalizations in the Cat.

In the cat four different types of vocalization, mews, howls, cries, and hisses were generated by microstimulation in different parts of the periaqueductal gray (PAG). While mews imply positive vocal expressions, howls, hisses, and cries represent negative vocal expressions. In the intermediate PAG, mews were generated in the lateral column, howls, and hisses in the ventrolateral column.

The physiological motor patterns produced by neurons in the nucleus retroambiguus in the rat and their modulation by vagal, peripheral chemosensory, and nociceptive stimulation.

The nucleus retroambiguus (NRA) is a neuronal cell group in the medullary ventrolateral tegmentum, rostrocaudally between the obex and the first cervical spinal segment. NRA neurons are premotor interneurons with direct projections to the motoneurons of soft palate, pharynx, and larynx in the nucleus ambiguus in the lateral medulla as well as to the motoneurons in the spinal cord innervating diaphragm, abdominal, and pelvic floor muscles and the lumbosacral motoneurons generating sexual posture. These NRA premotor interneurons receive very strong projections from the periaqueductal gray (PAG) in the context of basic survival mechanisms as fight, flight, freezing, sound production, and sexual behavior.

How the Emotional Motor System Controls the Pelvic Organs.

Introduction: The brain has two goals: survival of the individual and survival of the species. It ensures that the body resides in safe circumstances and can obtain sufficient drink and food. It also has to produce and protect offspring.

Two different motor systems are needed to generate human speech.

Vocalizations such as mews and cries in cats or crying and laughter in humans are examples of expression of emotions. These vocalizations are generated by the emotional motor system, in which the mesencephalic periaqueductal gray (PAG) plays a central role, as demonstrated by the fact that lesions in the PAG lead to complete mutism in cats, monkeys, as well as in humans. The PAG receives strong projections from higher limbic regions and from the anterior cingulate, insula, and orbitofrontal cortical areas.

Motor organization of positive and negative emotional vocalization in the cat midbrain periaqueductal gray.

Neurochemical microstimulation in different parts of the midbrain periaqueductal gray (PAG) in the cat generates four different types of vocalization, mews, howls, cries, and hisses. Mews signify positive vocal expression, whereas howls, hisses, and cries signify negative vocal communications. Mews were generated in the lateral column of the intermediate PAG and howls and hisses in the ventrolateral column of the intermediate PAG.

The midbrain periaqueductal gray changes the eupneic respiratory rhythm into a breathing pattern necessary for survival of the individual and of the species.

Modulation of respiration is a prerequisite for survival of the individual and of the species. For example, respiration has to be adjusted in case of speech, strenuous exercise, laughing, crying, or sudden escape from danger. Respiratory centers in pons and medulla generate the basic respiratory rhythm or eupnea, but they cannot modulate breathing in the context of emotional challenges, for which they need input from higher brain centers.

The periaqueductal gray controls brainstem emotional motor systems including respiration.

Respiration is a motor system essential for the survival of the individual and of the species. Because of its vital significance, studies on respiration often assume that breathing takes place independent of other motor systems. However, motor systems generating vocalization, coughing, sneezing, vomiting, as well as parturition, ejaculation, and defecation encompass abdominal pressure control, which involves changes in the respiratory pattern.

Stimulation of the midbrain periaqueductal gray modulates preinspiratory neurons in the ventrolateral medulla in the rat in vivo.

The midbrain periaqueductal gray (PAG) is involved in many basic survival behaviors that affect respiration. We hypothesized that the PAG promotes these behaviors by changing the firing of preinspiratory (pre-I) neurons in the pre-Bötzinger complex, a cell group thought to be important in generating respiratory rhythm. We tested this hypothesis by recording single unit activity of pre-Bötzinger pre-I neurons during stimulation in different parts of the PAG.

The CNS and bladder dysfunction.

The brain's role in the development and maintenance of bladder control is critical, although its precise role in patient-reported complaints such as urgency and urine leakage is unknown. Functional brain imaging studies have advanced our knowledge of brain activity during the micturition cycle, showing multiple neuronal circuits involved as parts of a 'brain-bladder control network.' Yet, new advances need to be made in order to incorporate this knowledge into existing models of neuroanatomy and of clinical syndromes of bladder dysfunction and related clinical practice.

High-intensity erotic visual stimuli de-activate the primary visual cortex in women.

Introduction: The primary visual cortex, Brodmann's area (BA 17), plays a vital role in basic survival mechanisms in humans. In most neuro-imaging studies in which the volunteers have to watch pictures or movies, the primary visual cortex is similarly activated independent of the content of the pictures or movies. However, in case the volunteers perform demanding non-visual tasks, the primary visual cortex becomes de-activated, although the amount of incoming visual sensory information is the same.

Midbrain and medullary control of postinspiratory activity of the crural and costal diaphragm in vivo.

Studies on brain stem respiratory neurons suggest that eupnea consists of three phases: inspiration, postinspiration, and expiration. However, it is not well understood how postinspiration is organized in the diaphragm, i.e.

Neurophysiology of the lower urinary tract.

The lower urinary tract (LUT) has two functions: (1) the storage of waste products in the form of urine and (2) the elimination of those wastes through micturition. The LUT operates in a simple "on-off" fashion, either storing urine or releasing it during voiding. While this activity may seem simple, micturition is controlled by a complex set of peripheral neurons that are, in turn, coordinated by cell groups in the spinal cord, brainstem, and brain.

Neuroanatomy of the lower urinary tract.

The lower urinary tract (LUT), which consists of the urinary bladder and its outlet, the urethra, is responsible for the storage and periodic elimination of bodily waste in the form of urine. The LUT is controlled by a complex set of peripheral autonomic and somatic nerves, which in turn are controlled through neural pathways in the spinal cord and brain. This influence of the central nervous system allows for the conscious control of the bladder, allowing the individual to choose an appropriate place to urinate.

Periaqueductal gray control of breathing.

Change of the basic respiratory rhythm (eupnea) is a pre-requisite for survival. For example, sudden escape from danger needs rapid shallow breathing, strenuous exercise requires tachypnea for sufficient supply of oxygen and a strong anxiety reaction necessitates gasping. Also for vocalization (and for speech in humans) an important mechanism for survival, respiration has to be changed.

The emotional motor system and micturition control.

Micturition is, similar to all other movements of the body, the result of activation of the motor system in the central nervous system. This review explains how the brain and brainstem control micturition. The basic reflex system begins with a distinct cell group called Gert's Nucleus (GN) in the sacral cord.

The nucleus retroambiguus control of respiration.

The role of the nucleus retroambiguus (NRA) in the context of respiration control has been subject of debate for considerable time. To solve this problem, we chemically (using d, l-homocysteic acid) stimulated the NRA in unanesthetized precollicularly decerebrated cats and studied the respiratory effect via simultaneous measurement of tracheal pressure and electromyograms of diaphragm, internal intercostal (IIC), cricothyroid (CT), and external oblique abdominal (EO) muscles. NRA-stimulation 0-1 mm caudal to the obex resulted in recruitment of IIC muscle and reduction in respiratory frequency.