Abstract
Spontaneous neuronal activity plays an important role in the development of cortical circuitry, yet its spatio-temporal dynamics are poorly understood. Cajal-Retzius (CR) neurons in developing layer 1 are necessary for correct cortical lamination and are strategically located to coordinate early circuit activity. To characterize the spontaneous activity of CR and other layer 1 neurons during cortical development, we imaged calcium transients in populations of layer 1 neurons in hemispheres and slices from postnatal rat somato-sensory neocortex. The spontaneous activity in layer 1 had complex spatio-temporal patterns. Groups of non-CR cells showed synchronous activations and formed networks of correlated neurons superimposed in the same territory. Correlated activity among non-CR cells was mediated by a depolarizing effect of GABA and was modulated by glutamate, probably released by CR cells. Our findings demonstrate that developing layer 1 can sustain complex patterns of correlated activity and reveal a circuit mechanism that can mediate this patterned activity.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Acetylcholine / pharmacology
-
Adrenergic alpha-Agonists / pharmacology
-
Animals
-
Calcium / metabolism
-
Cerebral Cortex / cytology*
-
Cerebral Cortex / growth & development*
-
Electric Stimulation
-
Excitatory Amino Acid Agonists / pharmacology
-
GABA Agonists / pharmacology
-
Glutamic Acid / pharmacology
-
Muscimol / pharmacology
-
N-Methylaspartate / pharmacology
-
Neurons / chemistry
-
Neurons / physiology*
-
Neurotransmitter Agents / metabolism
-
Norepinephrine / pharmacology
-
Organ Culture Techniques
-
Patch-Clamp Techniques
-
Rats
-
Rats, Sprague-Dawley
-
Synaptic Transmission / drug effects
-
Synaptic Transmission / physiology
-
Tetrodotoxin / pharmacology
-
Time Factors
-
alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / pharmacology
-
gamma-Aminobutyric Acid / physiology
Substances
-
Adrenergic alpha-Agonists
-
Excitatory Amino Acid Agonists
-
GABA Agonists
-
Neurotransmitter Agents
-
Muscimol
-
Glutamic Acid
-
Tetrodotoxin
-
gamma-Aminobutyric Acid
-
N-Methylaspartate
-
alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
-
Acetylcholine
-
Calcium
-
Norepinephrine