Spatial view cells are

neuron A neuron (American English), neurone (British English), or nerve cell, is an membrane potential#Cell excitability, excitable cell (biology), cell that fires electric signals called action potentials across a neural network (biology), neural net ...

s in

primate Primates is an order (biology), order of mammals, which is further divided into the Strepsirrhini, strepsirrhines, which include lemurs, galagos, and Lorisidae, lorisids; and the Haplorhini, haplorhines, which include Tarsiiformes, tarsiers a ...

hippocampus The hippocampus (: hippocampi; via Latin from Ancient Greek, Greek , 'seahorse'), also hippocampus proper, is a major component of the brain of humans and many other vertebrates. In the human brain the hippocampus, the dentate gyrus, and the ...

; they respond when a certain part of the environment is in the animal's

field of view The field of view (FOV) is the angle, angular extent of the observable world that is visual perception, seen at any given moment. In the case of optical instruments or sensors, it is a solid angle through which a detector is sensitive to elec ...

. They are related to

place cells A place cell is a kind of pyramidal neuron in the hippocampus that becomes active when an animal enters a particular place in its environment, which is known as the place field. Place cells are thought to act collectively as a cognitive represe ...

and

head direction cells Head direction (HD) cells are neurons found in a number of brain regions that increase their firing rates above baseline levels only when the animal's head points in a specific direction. They have been reported in rats, monkeys, mice, chinchillas a ...

. Spatial view cells differ from

, since they are not localized in space. They also differ from

since they don't represent a global orientation (like a

compass A compass is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose, which can pivot to align itself with No ...

), but the direction towards a specific object. Spatial view cells are the

cell Cell most often refers to: * Cell (biology), the functional basic unit of life * Cellphone, a phone connected to a cellular network * Clandestine cell, a penetration-resistant form of a secret or outlawed organization * Electrochemical cell, a de ...

s that respond in the

when a particular location is being recalled. These cells are identified in the

of test subjects by monitoring individual neurons while the test subject is moved around in a cue controlled spatial environment. The spatial view cells are the cells that fire consistently when the

monkey Monkey is a common name that may refer to most mammals of the infraorder Simiiformes, also known as simians. Traditionally, all animals in the group now known as simians are counted as monkeys except the apes. Thus monkeys, in that sense, co ...

is looking at a certain direction in the environment; this is independent of the head direction or the location of the monkey. Also, these cells are confirmed to be spatial view cells by observing that there is minimal randomized firing of the cells without the appropriate stimulus present.

Characteristics

Spatial view cells can be characterized by the following features: * respond to a region of visual space being looked at, relatively independently of where the

is located * respond to a small number of visual cues generally within a 30°

receptive field The receptive field, or sensory space, is a delimited medium where some physiological stimuli can evoke a sensory neuronal response in specific organisms. Complexity of the receptive field ranges from the unidimensional chemical structure of od ...

* activated when doing spatial tasks which include active walking in a spatial environment * fire relatively independent of the place where the

is located * represent the place at which the

is looking * generally stimulated by at least 3 cues present in optimal view * fire uniformly all over different areas in space as long as

is looking at the same area * ability to maintain their spatial properties for periods of up to several minutes in the dark * responses depend on where the

is looking, by measuring eye position * spatial representation is allocentric * responses still occur in some cases even if view details are obscured with

curtain A curtain is a piece of cloth or other material intended to block or obscure light, air drafts, or (in the case of a shower curtain) water. Curtains are often hung on the inside of a building's windows to block the passage of light. For instan ...

s The spatial view cells that respond in the absence of visual cues are generally found in the

Cornu Ammonis area 1 The hippocampal subfields are four subfields CA1, CA2, CA3, and CA4 that make up the structure of the hippocampus. Regions described in the hippocampus are the head, body, and tail, and other hippocampal subfields include the dentate gyrus, the ...

, the

parahippocampal gyrus The parahippocampal gyrus (or hippocampal gyrus') is a grey matter cortical region, a gyrus of the brain that surrounds the hippocampus and is part of the limbic system. The region plays an important role in memory encoding and retrieval. It ha ...

, and the presubiculum, while the ones that do not respond are found in the Cornu Ammonis region 3. The cells found in the CA1,

, and presubiculum regions often provide a longer response even after the stimulus is removed for up to several minutes in complete

darkness Darkness is the condition resulting from a lack of illumination, or an absence of visible light. Human vision is unable to distinguish colors in conditions of very low luminance because the hue-sensitive photoreceptor cells on the retina a ...

. Spatial view cells update their representations by the use of

idiothetic Idiothetic literally means "self-proposition" (Greek derivation), and is used in navigation models (e.g., of a rat in a maze) to describe the use of self-motion cues, rather than allothetic, or external, cues such as landmarks, to determine posit ...

inputs in the dark and these cells are commonly found in the CA1,

, and presubiculum regions.

Uses

Spatial view cells are used by

primates Primates is an order of mammals, which is further divided into the strepsirrhines, which include lemurs, galagos, and lorisids; and the haplorhines, which include tarsiers and simians ( monkeys and apes). Primates arose 74–63 ...

for storing an

episodic memory Episodic memory is the memory of everyday events (such as times, location geography, associated emotions, and other contextual information) that can be explicitly stated or conjured. It is the collection of past personal experiences that occurred ...

that helps with remembering where a particular object was in the environment. Imaging studies have shown that the hippocampus plays an important role in spatial navigation and episodic memories. Also, spatial view cells enable them to recall locations of objects even if they are not physically present in the environment. The

neurons A neuron (American English), neurone (British English), or nerve cell, is an membrane potential#Cell excitability, excitable cell (biology), cell that fires electric signals called action potentials across a neural network (biology), neural net ...

associated with remembering the location and object are often found in the

. These spatial view cells do not only recall specific locations, but they also remember

distances Distance is a numerical or occasionally qualitative measurement of how far apart objects, points, people, or ideas are. In physics or everyday usage, distance may refer to a physical length or an estimation based on other criteria (e.g. "two co ...

between other

landmarks A landmark is a recognizable natural or artificial feature used for navigation, a feature that stands out from its near environment and is often visible from long distances. In modern-day use, the term can also be applied to smaller structures ...

around the place in order to gain a better understanding of where the places are spatially. In real world applications,

monkeys Monkey is a common name that may refer to most mammals of the infraorder Simiiformes, also known as simians. Traditionally, all animals in the group now known as simians are counted as monkeys except the apes. Thus monkeys, in that sense, co ...

remember where they saw ripe

fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

with the aid of spatial view cells.

Humans Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...

use spatial view cells when they try to recall where they may have seen a person or where they left their keys. Primates' highly developed visual and

eye movement Eye movement includes the voluntary or involuntary movement of the eyes. Eye movements are used by a number of organisms (e.g. primates, rodents, flies, birds, fish, cats, crabs, octopus) to fixate, inspect and track visual objects of inte ...

control systems enables them to explore and remember information about what's present at places in the environment without having to physically visit those places. These sorts of

memories Memory is the faculty of the mind by which data or information is Encoding (memory), encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future Action (philosophy), action. I ...

would be useful for spatial

navigation Navigation is a field of study that focuses on the process of monitoring and controlling the motion, movement of a craft or vehicle from one place to another.Bowditch, 2003:799. The field of navigation includes four general categories: land navig ...

in which the

visualize everything in an allocentric, or worldly manner that allows them to convey directions to others without physically going through the entire route. These cells are used by primates in regular day-to-day lives.

Removal of spatial view cell

Diseases A disease is a particular abnormal condition that adversely affects the structure or function of all or part of an organism and is not immediately due to any external injury. Diseases are often known to be medical conditions that are asso ...

and

illnesses A disease is a particular abnormal condition that adversely affects the structure or function of all or part of an organism and is not immediately due to any external injury. Diseases are often known to be medical conditions that are asso ...

that harm the

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

and the

can also damage spatial view cells, which are located in the hippocampus.

Stroke Stroke is a medical condition in which poor cerebral circulation, blood flow to a part of the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemor ...

meningitis Meningitis is acute or chronic inflammation of the protective membranes covering the brain and spinal cord, collectively called the meninges. The most common symptoms are fever, intense headache, vomiting and neck stiffness and occasion ...

, and

encephalitis Encephalitis is inflammation of the Human brain, brain. The severity can be variable with symptoms including reduction or alteration in consciousness, aphasia, headache, fever, confusion, a stiff neck, and vomiting. Complications may include se ...

are only a few of the various illnesses that can cause harm to the spatial view cells. Some clinical

symptoms Signs and symptoms are diagnostic indications of an illness, injury, or condition. Signs are objective and externally observable; symptoms are a person's reported subjective experiences. A sign for example may be a higher or lower temperature ...

present in

patients A patient is any recipient of health care services that are performed by healthcare professionals. The patient is most often ill or injured and in need of treatment by a physician, nurse, optometrist, dentist, veterinarian, or other healt ...

with damage to the

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity o ...

include:

fever Fever or pyrexia in humans is a symptom of an anti-infection defense mechanism that appears with Human body temperature, body temperature exceeding the normal range caused by an increase in the body's temperature Human body temperature#Fever, s ...

altered mental status An altered level of consciousness is any measure of arousal other than normal. Level of consciousness (LOC) is a measurement of a person's arousability and responsiveness to stimuli from the environment. A mildly depressed level of consciousne ...

, and

neck stiffness Neck stiffness, stiff neck and nuchal rigidity are terms often used interchangeably to describe the medical condition when one experiences discomfort or pain when trying to turn, move, or flex the neck. Possible causes include muscle strain or sp ...

Lesion A lesion is any damage or abnormal change in the tissue of an organism, usually caused by injury or diseases. The term ''Lesion'' is derived from the Latin meaning "injury". Lesions may occur in both plants and animals. Types There is no de ...

studies have shown that damage to the hippocampus or to some of its connections, such as the fornix, in monkeys produces deficits in

learning Learning is the process of acquiring new understanding, knowledge, behaviors, skills, value (personal and cultural), values, Attitude (psychology), attitudes, and preferences. The ability to learn is possessed by humans, non-human animals, and ...

about the places of objects and about the places where responses should be made. This sort of damage to the brain often results in impaired object-place memory. Object-place memory tasks require the monkey to not only remember the object seen, but they must also remember where the object was seen in the environment. It has been shown that posterior para-hippocampal lesions in

macaques The macaques () constitute a genus (''Macaca'') of gregarious Old World monkeys of the subfamily Cercopithecinae. The 23 species of macaques inhabit ranges throughout Asia, North Africa, and Europe (in Gibraltar). Macaques are principally fru ...

impair even a simple type of object-place learning in which only one pair of unique stimuli are needed for memory.

Relationship to other diseases

Patients A patient is any recipient of health care services that are performed by healthcare professionals. The patient is most often ill or injured and in need of treatment by a physician, nurse, optometrist, dentist, veterinarian, or other healt ...

with damage to spatial view cells will often show similar symptoms from other

diseases A disease is a particular abnormal condition that adversely affects the structure or function of all or part of an organism and is not immediately due to any external injury. Diseases are often known to be medical conditions that are asso ...

such as: vascular dementia,

Alzheimer's disease Alzheimer's disease (AD) is a neurodegenerative disease and the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in remembering recent events. As the disease advances, symptoms can include problems wit ...

, amnesia fugue,

macular degeneration Macular degeneration, also known as age-related macular degeneration (AMD or ARMD), is a medical condition which may result in blurred vision, blurred or vision loss, no vision in the center of the visual field. Early on there are often no sym ...

, and optic nerve damage.Dr. Manish N. Patel, Resident Physician at St. Vincent's Medical Center Department of Family Medicine. Interview date October 19th, 2010. Another illness that reflects signs of spatial view damage is fornix lesions that impair conditional left–right discrimination learning. Patients with damage to the

temporal lobe The temporal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The temporal lobe is located beneath the lateral fissure on both cerebral hemispheres of the mammalian brain. The temporal lobe is involved in pr ...

which also includes the

can sometimes have

amnesia Amnesia is a deficit in memory caused by brain damage or brain diseases,Gazzaniga, M., Ivry, R., & Mangun, G. (2009) Cognitive Neuroscience: The biology of the mind. New York: W.W. Norton & Company. but it can also be temporarily caused by t ...

. Patients with amnesia often have memory impairments in which they have difficulty remembering both what they saw and where they saw the object or event take place. These signs point to the possible damage to spatial view cells found in the hippocampus.

Current research involving spatial view cells

Optimal firing rate

Current research shows that the maximum firing rate of spatial view cells is obtained when the test agent is allowed to explore the environment freely. Tests in which the

was not allowed to have active locomotion provided very few results of spatial view cells being detected in the

. Majority of the

experiment An experiment is a procedure carried out to support or refute a hypothesis, or determine the efficacy or likelihood of something previously untried. Experiments provide insight into cause-and-effect by demonstrating what outcome occurs whe ...

s conducted for spatial view cells involved the use of

macaque The macaques () constitute a genus (''Macaca'') of gregarious Old World monkeys of the subfamily Cercopithecinae. The 23 species of macaques inhabit ranges throughout Asia, North Africa, and Europe (in Gibraltar). Macaques are principally f ...

as test subjects. These types of cells are identified by monitoring the hippocampus of the monkeys while the brains are stimulated by presenting various images and objects in the monkey's vision. Various researchers use different

methodologies In its most common sense, methodology is the study of research methods. However, the term can also refer to the methods themselves or to the philosophical discussion of associated background assumptions. A method is a structured procedure for bri ...

in sync with the experiment being conducted in order to identify these spatial view cells. For example, in a delayed spatial response task, the monkey is shown a stimulus on one side of a screen and then the stimulus is taken away. After a short while, the stimulus is again presented to the monkey in the same location and the firing of the cell in the hippocampus that is specifically associated with the location at which the monkey is looking and is independent of the location of the monkey helps identify the spatial view cell. The monkeys in this of experiment are encouraged by rewarding them with

fruit juice Juice is a drink made from the extraction or pressing of the natural liquid contained in fruit and vegetables. It can also refer to liquids that are flavored with concentrate or other biological food sources, such as meat or seafood, such ...

when they correctly identify the same object in the same location twice in a row and if they get it incorrect, the monkeys receive a saline taste.

Association with episodic memories

The experiments often use object-place memory tasks because they are representative of

episodic memories Episodic memory is the memory of everyday events (such as times, location geography, associated emotions, and other contextual information) that can be explicitly stated or conjured. It is the collection of past personal experiences that occurred ...

and often employ similar parts of the

. It is also believed that whenever an episodic memory is stored, part of the context from that event is also stored along with it. As a result, recalling a certain place can link up the

emotions Emotions are physical and mental states brought on by neurophysiology, neurophysiological changes, variously associated with thoughts, feelings, behavior, behavioral responses, and a degree of pleasure or suffering, displeasure. There is ...

at that time. These recollections do not only happen if a place is recalled, but they are prone to occur if the person is in the same mood as they were at the time of the event. Rewards are also remembered along with the place at which it was received. Spatial view cells have been proven to be independent of head direction and place cells. Spatial view cells have been shown to respond even in the dark without any visual cues as long as the test subject was facing in the proper direction. It is believed that in the absence of visual cues, spatial view cells respond from the inputs being received from

and

along with eye position of the

. The use of the

vestibular system The vestibular system, in vertebrates, is a sensory system that creates the sense of balance and spatial orientation for the purpose of coordinating motor coordination, movement with balance. Together with the cochlea, a part of the auditory sys ...

and proprioceptive cues also provide a sense of direction the animal is facing in the dark.

Ability to update with new information

Research has led to the finding the spatial view cells are consistently updated with other inputs from the body. For example, when a monkey is oriented in a different position spatially such as being upside down, the spatial view cells still respond when the test subject faces the appropriate direction. This implies that there is stream of new information being received by the spatial view cells constantly. This integration from various inputs develops continuous attractor networks. Continuous attractor neural networks, also known as CANN, are routinely used when studying spatial view cells from an

stand point. CANNs allow researchers to closely monitor the associated

and

along with the spatial view cells as one close "packet of neural activity".

References

{{reflist Hippocampus (brain)