Wnt Signaling Mediates Experience-Related Regulation of Synapse Numbers and Mossy Fiber Connectivities in the Adult Hippocampus

نویسندگان

  • Nadine Gogolla
  • Ivan Galimberti
  • Yuichi Deguchi
  • Pico Caroni
چکیده

We investigated how experience regulates the structure of a defined neuronal circuit in adult mice. Enriched environment (EE) produced a robust and reversible increase in hippocampal stratum lucidum synapse numbers, mossy fiber terminal (LMT) numbers, and spine plus synapse densities at LMTs, whereas a distinct mechanism depending on Rab3a promoted LMT volume growth. In parallel, EE increased postsynaptic CA3 pyramidal neuron Wnt7a/b levels. Inhibiting Wnt signaling through locally applied sFRP-1 suppressed the effects of EE on synapse numbers and further reduced synapse numbers in control mice. Wnt7 applied to CA3 mimicked the effects of EE on synapse and LMT numbers. CA3 Wnt7a/b levels were enhanced by excitatory activity and reduced by sFRP-1. Synapse numbers and Wnt7a/b levels peaked in mice aged 6-12 months; a decline in aged mice was reversed by EE. Therefore, behavioral experience specifically regulates adult global stratum lucidum synapse numbers and hippocampal network structure through Wnt signaling.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Stress-related effects on neuronal morphology and choline acetyltransferase activity in the hippocampus

The effects of semi-chronic stress on neuronal morphology and choline acetyltransferase were studied by injecting rats with dexamethasone. It was found that in the dexamethasone-treated rats the choline acetyltransferase activity had increased in the area where the fibers from the perforant pathway synapse with the granular cell layer of the dentate gyrus and also where the mossy fibers of the ...

متن کامل

Stress-related effects on neuronal morphology and choline acetyltransferase activity in the hippocampus

The effects of semi-chronic stress on neuronal morphology and choline acetyltransferase were studied by injecting rats with dexamethasone. It was found that in the dexamethasone-treated rats the choline acetyltransferase activity had increased in the area where the fibers from the perforant pathway synapse with the granular cell layer of the dentate gyrus and also where the mossy fibers of the ...

متن کامل

Wnt7a signaling promotes dendritic spine growth and synaptic strength through Ca²⁺/Calmodulin-dependent protein kinase II.

The balance between excitatory and inhibitory synapses is crucial for normal brain function. Wnt proteins stimulate synapse formation by increasing synaptic assembly. However, it is unclear whether Wnt signaling differentially regulates the formation of excitatory and inhibitory synapses. Here, we demonstrate that Wnt7a preferentially stimulates excitatory synapse formation and function. In hip...

متن کامل

GABA-mediated membrane oscillations as coincidence detectors for enhancing synaptic efficacy in the developing hippocampus

Spontaneously occurring neuronal oscillations constitute a hallmark of developmental networks. They have been observed in the retina, neocortex, hippocampus, thalamus and spinal cord. In the immature hippocampus the so-called ‘giant depolarizing potentials’ (GDPs) are network-driven membrane oscillations characterized by recurrent membrane depolarization with superimposed fast action potentials...

متن کامل

B-ephrin reverse signaling is required for NMDA-independent long-term potentiation of mossy fibers in the hippocampus.

The mossy fiber to CA3 pyramidal neuron synapse in the hippocampus displays an atypical form of NMDA receptor-independent long-term potentiation (LTP). Plasticity at this synapse is expressed in the presynaptic terminal as an elevated probability of neurotransmitter release. However, evidence indicates that postsynaptic mechanisms and trans-synaptic signaling through an association between post...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Neuron

دوره 62  شماره 

صفحات  -

تاریخ انتشار 2009