Cck Interneurons (Hippocampus) plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.
| Taxonomy |
ID |
Name / Label |
| Cell Ontology (CL) |
CL:0002277 |
type I enteroendocrine cell |
| Database |
ID |
Name |
Confidence |
| Cell Ontology |
CL:0002277 |
type I enteroendocrine cell |
Medium |
Cholecystokinin (CCK)-expressing interneurons constitute a major class of inhibitory neurons in the hippocampus that play crucial roles in regulating circuit excitability, oscillatory activity, and information processing. These cells are essential for maintaining the balance between excitation and inhibition, and their dysfunction has been implicated in various neurodegenerative diseases including Alzheimer's disease and Parkinson's disease.
¶ Molecular Markers and Neurochemistry
CCK interneurons are defined by their expression of cholecystokinin, a peptide neurotransmitter that acts on CCK receptors (CCK-A and CCK-B subtypes):
- CCK: The defining neuropeptide marker
- CCKAR (CCK-A receptor): Peripheral and some central expression
- CCKBR (CCK-B receptor): Predominant in the brain
- CKB: Brain-type creatine kinase
- PP: Pancreatic polypeptide (subset)
- VIP: Vasoactive intestinal peptide (subset)
CCK interneurons frequently co-express other neurochemical markers:
| Marker |
Expression |
Functional Implications |
| CB1 cannabinoid receptor |
High |
Retrograde signaling |
| Parvalbumin |
Subset |
Fast spiking |
| Reelin |
Subset |
Development |
| NPY |
Some subtypes |
Modulation |
CCK interneurons exhibit remarkable morphological heterogeneity:
- Axonal arbors densely targeting pyramidal cell somata
- Formation of perisomatic inhibitory synapses
- Critical for controlling pyramidal neuron output
- Distinct from parvalbumin basket cells
- Axons innervating dendritic shafts and spines
- Regulation of excitatory inputs
- Input-specific inhibition
- Target dendritic spines on Schaffer collateral axons
- Feedforward inhibition
- Timing-dependent modulation
- Neuropeptide Y co-expression
- Slow-spiking properties
- Dense axonal labeling in stratum lucidum
CCK interneurons display diverse firing patterns:
- Adapting firing: Progressive decrease in firing rate
- Burst-firing: Initial high-frequency burst
- Fast-spiking: Some CCK/PV co-expressing cells
- Low-threshold spiking: Subset with rebound properties
| Property |
Characteristic |
Significance |
| Synaptic release |
High release probability |
Powerful inhibition |
| CB1 modulation |
Presynaptic inhibition |
Plasticity |
| Target specificity |
Somatic vs dendritic |
Differential control |
| Unitary conductance |
1-2 nS |
Strong connections |
CCK interneurons receive diverse synaptic inputs:
- Local collaterals: From CA3 and CA1 pyramidal neurons
- Feedback inhibition: Reciprocal connections
- Subcortical inputs: From septum and brainstem
- Chandelier cell inputs: Interneuron-specific
- CA1/CA3 pyramidal neuron somata: Basket cells
- Dendritic shafts: Dendrite-targeting cells
- Other interneurons: Disinhibitory circuits
- Extrinsic targets: Entorhinal cortex, subiculum
CCK interneurons contribute to theta rhythm generation and modulation:
- Phase-locked firing during theta
- Entrainment of pyramidal neuron timing
- Coordination of burst firing
- Spatial navigation support
CCK basket cells are crucial for gamma generation:
- Synchronization of pyramidal cells
- PING (pyramidal-interneuron gamma) mechanism
- ASSEMBLY (interneuron network gamma)
- Cognitive processing facilitation
- CCK interneuron silencing during ripples
- Ripple initiation mechanisms
- Memory consolidation support
CCK interneurons show specific vulnerabilities in AD:
- Amyloid-beta toxicity: Direct effects on CCK neurons
- Early dysfunction: Precedes plaque formation
- Network hyperexcitability: Loss of somatic inhibition
- Circuit remodeling: Compensatory changes
-
Amyloid-beta effects:
- Reduced CCK expression
- Impaired GABA release
- Synaptic dysfunction
-
Tau pathology:
- Neuronal loss in CCK populations
- Connectivity disruption
-
Network dysfunction:
- Hyperexcitability
- Seizure susceptibility
- Memory circuit impairment
| Approach |
Target |
Status |
| CCK agonists |
CCKBR |
Research |
| CB1 antagonists |
Cannabinoid |
Research |
| GABA modulation |
GABA-A |
Clinical |
| CCK gene therapy |
CCK expression |
Preclinical |
CCK signaling modulates striatal function:
- DopamineCCK interactions
- Motor control modulation
- L-DOPA response
- CCK involvement in L-DOPA-induced dyskinesias
- CCK antagonist potential
- Rodent CCK distribution well characterized
- Primate studies reveal additional populations
- Human hippocampal CCK chemistry being mapped
- CCK expression develops postnatally
- Critical periods for circuit formation
- Experience-dependent plasticity
- CCK-Cre driver lines
- CCK immunostaining
- In situ hybridization
- Reporter mice
- Optogenetic manipulation
- Chemogenetic silencing/activation
- Patch-clamp electrophysiology
- Calcium imaging
- Freund TF, Katona I. Perisomatic inhibition. Neuron. 2007
- Bartos M, et al. Synaptic mechanisms of synchronized gamma oscillations. Nat Rev Neurosci. 2007
- Palop JJ, Mucke L. Epilepsy and hyperexcitability in Alzheimer's disease. Nat Neurosci. 2010
- Klausberger T, Somogyi P. Neuronal diversity and temporal dynamics. Science. 2008
- Cossart R. The maturation of cortical interneuron diversity. Nat Neurosci. 2014
- [CA1 Pyramidal Neurons
- Parvalbumin Interneurons
- Hippocampal Interneurons](/cell-types/ca1-pyramidal-neurons
--parvalbumin-interneurons
--hippocampal-interneurons)
- Alzheimer Disease
- [GABA Signaling
- CCK Signaling
](/mechanisms/gaba-signaling
--cck-signaling)##