Rhinal cortex
Encyclopedia
The rhinal cortex is the cortex surrounding the rhinal fissure
, including the entorhinal cortex
and the perirhinal cortex
.
It is a cortical
region in the medial temporal lobe that is made up of Brodmann areas 28, 34, 35 and 36.
Input from all sensory
cortexes
flows to the perirhinal
and parahippocampal cortexes
, from where it continues to the entorhinal cortex
, and proceeds to the hippocampus
. After feedback from the hippocampus it then returns the same way back to the sensory cortexes.
.
Studies comparing the results of selective lesions to the hippocampus
and to the rhinal cortex, found that lesions to the hippocampus only did not cause impairment on object recognitions tests, but lesions to the rhinal cortex only, caused severe anterograde
and retrograde
impairments on object recognition tests. The conclusion was that object recognition (semantic memory
) depends on the rhinal cortex.
Rhinal fissure
In the human brain, the rhinencephalon appears as a longitudinal elevation, with a corresponding internal furrow, on the under surface of the hemisphere close to the lamina terminalis; it is separated from the lateral surface of the hemisphere by a furrow, the external rhinal fissure , and is...
, including the entorhinal cortex
Entorhinal cortex
The entorhinal cortex is located in the medial temporal lobe and functions as a hub in a widespread network for memory and navigation. The EC is the main interface between the hippocampus and neocortex...
and the perirhinal cortex
Perirhinal cortex
Perirhinal cortex is a cortical region in the medial temporal lobe that is made up of Brodmann areas 35 and 36. In rats, it is located along and dorsal to the rhinal sulcus. It receives highly-processed sensory information from all sensory regions, and is generally accepted to be an important...
.
It is a cortical
Cerebral cortex
The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...
region in the medial temporal lobe that is made up of Brodmann areas 28, 34, 35 and 36.
Input from all sensory
Sensory
Sensory may refer to:relating to senses or smellIn biology:* Sensory preference* Sensory system, part of the nervous system of organisms* Sensory neuron, nerve cell responsible for transmitting information about external stimuli...
cortexes
Cerebral cortex
The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...
flows to the perirhinal
Perirhinal cortex
Perirhinal cortex is a cortical region in the medial temporal lobe that is made up of Brodmann areas 35 and 36. In rats, it is located along and dorsal to the rhinal sulcus. It receives highly-processed sensory information from all sensory regions, and is generally accepted to be an important...
and parahippocampal cortexes
Parahippocampal gyrus
The parahippocampal gyrus is a grey matter cortical region of the brain that surrounds the hippocampus. This region plays an important role in memory encoding and retrieval....
, from where it continues to the entorhinal cortex
Entorhinal cortex
The entorhinal cortex is located in the medial temporal lobe and functions as a hub in a widespread network for memory and navigation. The EC is the main interface between the hippocampus and neocortex...
, and proceeds to the hippocampus
Hippocampus
The hippocampus is a major component of the brains of humans and other vertebrates. It belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory and spatial navigation. Humans and other mammals have two hippocampi, one in...
. After feedback from the hippocampus it then returns the same way back to the sensory cortexes.
Explicit memory
The rhinal cortex is proposed to be part of the neural circuit for explicit memoryExplicit memory
Explicit memory is the conscious, intentional recollection of previous experiences and information. People use explicit memory throughout the day, such as remembering the time of an appointment or recollecting an event from years ago....
.
Studies comparing the results of selective lesions to the hippocampus
Hippocampus
The hippocampus is a major component of the brains of humans and other vertebrates. It belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory and spatial navigation. Humans and other mammals have two hippocampi, one in...
and to the rhinal cortex, found that lesions to the hippocampus only did not cause impairment on object recognitions tests, but lesions to the rhinal cortex only, caused severe anterograde
Anterograde amnesia
Anterograde amnesia is a loss of the ability to create new memories after the event that caused the amnesia, leading to a partial or complete inability to recall the recent past, while long-term memories from before the event remain intact. This is in contrast to retrograde amnesia, where memories...
and retrograde
Retrograde amnesia
Retrograde amnesia is a loss of access to events that occurred, or information that was learned, before an injury or the onset of a disease....
impairments on object recognition tests. The conclusion was that object recognition (semantic memory
Semantic memory
Semantic memory refers to the memory of meanings, understandings, and other concept-based knowledge unrelated to specific experiences. The conscious recollection of factual information and general knowledge about the world is generally thought to be independent of context and personal relevance...
) depends on the rhinal cortex.