Abstract
Deficits in social cognition and behavior are a hallmark of many psychiatric disorders. The medial extended amygdala, including the medial amygdala and the medial bed nucleus of the stria terminalis, is a key component of functional networks involved in sociality. However, this nuclear complex is highly heterogeneous and contains numerous GABAergic and glutamatergic neuron subpopulations. Deciphering the connections of different neurons is essential in order to understand how this structure regulates different aspects of sociality, and it is necessary to evaluate their differential implication in distinct mental disorders. Developmental studies in different vertebrates are offering new venues to understand neuronal diversity of the medial extended amygdala, and are helping to establish a relation between the embryonic origin and molecular signature of distinct neurons with the functional subcircuits in which they are engaged. These studies have provided many details on the distinct GABAergic neurons of the medial extended amygdala, but information on the glutamatergic neurons is still scarce. Using an Otp-eGFP transgenic mouse and multiple fluorescent labeling, we show that most glutamatergic neurons of the medial extended amygdala originate in a novel telencephalo-opto-hypothalamic embryonic domain (TOH), located at the transition between telencephalon and hypothalamus, which produces Otp-lineage neurons expressing the telencephalic marker Foxg1 but not Nkx2.1 during development. These glutamatergic cells include a subpopulation of projection neurons of the medial amygdala, which activation has been previously shown to promote autistic-like behavior. Our data open new venues for studying the implication of this neuron subtype in neurodevelopmental disorders producing social deficits.
Competing Interest Statement
The authors have declared no competing interest.
Abbreviations
- AAv
- ventral anterior amygdala
- ac
- anterior commissure
- AH
- anterior hypothalamus
- BC
- amygdalar basolateral complex
- BMa
- basomedial amygdala, anterior subnucleus
- BSTM
- medial bed nucleus of the stria terminalis
- BSTMa
- BSTM, anterior division
- BSTMh
- BSTM, hypothalamic subdivision/ hypothalamic subdivision of BSTM
- BSTMp
- BSTM, posterior division
- BSTL
- lateral bed nucleus of the stria terminalis
- Ce
- central nucleus of the amygdala (or simply central amygdala)
- Cer
- cerebellum
- CPu
- caudate-putamen complex
- DM
- dorsomedial hypothalamic nucleus
- EM
- median eminence
- ESO
- episupraoptic nucleus
- f
- fornix
- GP
- globus pallidus
- HF
- hippocampal formation
- Hya
- alar hypothalamus
- Hyb
- basal hypothalamus
- LH
- lateral hypothalamus
- LH
- basal LH
- LOT
- nucleus of the lateral olfactory tract
- LPO
- lateral preoptic area
- lv
- lateral ventricle
- m
- mantle
- Ma
- mammillary nuclei
- Me
- medial nucleus of the amygdala (or simply, medial amygdala)
- MeA
- anterior subnucleus of Me
- MeP
- posterior subnucleus of Me
- MePD
- dorsal subnucleus of MeP
- MePV
- ventral subnucleus of MeP
- MePVm
- medial branch of MePV
- MePVl
- lateral branch of MePV
- MGEvc
- medial glaglionic eminence, ventrocaudal subdivision
- NH
- neurohypophysis
- OB
- olfactory bulb
- oc
- optic chiasm
- op
- optic pedicle
- ot
- optic tract
- P
- pallium
- Pad
- paraventricular nucleus, dorsal subdivision
- Pav
- paraventricular nucleus, ventral subdivision
- Pt
- pretectum
- PHy
- peduncular hypothalamus
- POPe
- periventricular part of the preoptic area
- POs
- subpallial preoptic area
- POv
- ventral preoptic area
- PTh
- prethalamus
- PThE
- prethalamic eminence
- PVN
- paraventricular nucleus, principal subdivision
- Se
- septum
- SEA
- sublenticular extended amygdala
- SO
- supraoptic nucleus, principal subdivision
- SOt
- supraoptic nucleus, terminal subdivision
- SOtu
- of the supraoptic nucleus, tuberal subdivision
- Sp
- subpallium
- SC
- superior colliculus
- SCN
- suprachiasmatic nucleus
- SPa
- subparaventricular region
- SPV
- supraopto-paraventricular hypothalamic domain (classical definition)
- SPVc
- supraopto-paraventricular hypothalamic domain, core part
- svz
- subventricular zone
- Tel
- telencephalon
- Th
- thalamus
- THy
- terminal hypothalamus
- TOH
- telencephalo-opto-hypothalamic embryonic domain
- VMH
- ventromedial hypothalamic nucleus
- vz
- ventricular zone
- 3v
- third ventricle
- 4v
- fourth ventricle
