Systems Neurophysiology Evidence Flashcards
Baroreceptors- ASIC2 involvement
Lu et al
mRNA in NG/ Aortic Arch Immunofluorescence KOs -increased hr, map -reduced locomotor activity and brs -atropine/ propanolol response
ADN stimulation no differences
-asic2 kos had higher starting bp
mRNA- cells with more ASIC2 showed greater APs in response to mechanical stim
Overexpression
Baroreceptors- TRPC5 involvement
Lau et al
Similar responses to ASIC2
Projection of Baroreceptive cells to NTS
WHBS prep
Anterograde tracing
NTS activity patch clamp
NTS to NA
Deuchars, Mendelowitz
NA EPSCs generated with NTS stimulation
NMDA agonists/antagonists
CIH Rats (Yan et al)
- reduced response to NA stimulation
Nissl staining NA loss
NTS to DMNx
Cheng
Electrical Activity
Anterograde tracer- cardiac ganglion
EPSPs from different sources
Sympathetic pathway blood pressure (IML and rVLM)
Deuchars and lall
Psuedorabies virus labelling
IML stimulation
Role of rVLM
Glutamate injection
Optogenetics
- conscious vs. unconscious
cVLM to rVLM
Kynurenate (Glu Antagonist) to NTS
Bicucculine (GABA antagonist to rVLM)
Paraventricular Nucleus exercise control
Higa-Taniguchi:
Exercise trained mice induced noradrenergic fibres in PVN (immunoreactivity)
Koba 2017:
Optogenetics into PVN
Emotional regulation mPFC
Westerhaus and Loewry
PRV into adrenal, stellate, mesenteric ganglia
Central Autonomic Area
Bacon and Smith
KCl and (PHA-L)
Function of the mPFC
Extra reading
fMRI of vmPFC and HR
MSNA and HR
Cortical BOLD and mPFC activity with MSNA
CAA to IML (GABAergic neuron)
Deuchars
FISH- GAD67
Electrophysiological
Bicucculine vs Kynurenate
Innocuous Temperature Receptors
Bautista & Mogrich
Dual chamber assay
Lateral Parabrachial Nucleus (Morrison)
Anterograde/retrograde tracers
Temp-dependent AP changes correlated with BAT activity (SNA)
Muscimol
MnPO and MPA
Bicucculine administration to MnPO
Muscimol administration to DMH
Afferent pathway of thermoregulation
Oldfield et al
PRV injection into BAT
T3 to T6
Stellate ganglion
Raphe Pallidus
Confirming raphe pallidus neurons
PRV double stained with Trytophan Hydroxylase
Role of 5-HT Raphe neurons
5-HT injection
Muscimol
c-fos activity (Hale)
lmx1b KO mice (Hodges)
Respiratory pattern recordings
Pre-Inspiratory Hypoglossal Burst
Augmenting Phrenic Burst
Decrementing Post-inspiratory discharge (Vagus)
BotC role
Smith slices
Optogenetics
NK1R-expressing BotC cells
Antibody of NK1R cells applied
-Plethysomography- loss of appt. responses to hyperoxia and hypercapnia
SST-expressing cells
Inhibitory Allostatin receptor
- cessation of breathing
CreRecombinase ChR2 expression rescue
Inhibitory preBotC cells
Optogenetics-glycinergics
Swallowing, delayed onset/ prematurely terminated
BotC and PiCo
Smith, Nino Ramirez
Ramirez: imaging showed PiCo activity
Optogenetics in model with pons
Lateral Parafacial Nucleus/RTN role
Chemogenetic inhibition- rest vs. exercise
Lavezzi- hyperplasia unexplained death
ccRTNs (Guyunet)
Electrical recording with increased CO2
Optogenetics- activation and connection to rVRG(ChR2-mcherry)
Acidification in vivo
GPR4/TASK2 role
Kumar
FISH staining
c-fos on CO2 perfusion
KOs and rescue
Raphe Obscurus role (Richerson)
CSF acidification w/ buffering
Lesioning of 5-HT
Hodges (Lmx1b KO)
Optogenetics- RR and dEMG
-hypercapnia differential results
Combined theory (Nattie)
(Nattie and Li):
Orexin neurons PeF
OX1R/OX2R antagonists
Ventilatory response in wakefulness
PeF stimulation (Fortuna): Gabazine- c-fos, CO2 PND and MAP changes
Glial Cells in Chemoreception
ATP administration to ventral brainstem
Antagonism of P2X receptors recording Phox2b action potentials
Optogenetic stimulation of astrocytes
-P2X antagonist abolishable
Phox2B in Congential Central Hypoventilation Syndrome
Knock-in mouse model
- absence of cells- lavezzi
- respiratory function
- hypoglossal activity
- intracellular calcium reduced in RTN
No preBotC/ Raphe differences
MYO1H in CCHS
Inappropriate response to hypercapnia
Desogestrel as a treatment for CCHS - patient studies
Joubert
Patients on Desogestrel showed RR improvements, stopping treatment attenuated improvements
Desogestrel as a treatment for CCHS - mouse studies
Joubert
Etonogestrel (ETO)
- similar responses in mice
Ex vivo:
- RR in medullary prep
- no c-fos changes in RTN
- Bicucculine attentuated response
- NMDA/5-HT enhanced response
AgRP neurons action
Optogenetics (Aponte)
Chemogenetics
DREADD (excitatory and inhibitory) (Krashes)
Leptin and ghrelin action (firing rate)
AgRP neurons inhibiting POMC
Atasoy
Optogenetics
AgRP-ChR2 with POMC-eGFP
POMC stimulation
Simultaneous
POMC reducing food intake
Optogenetics
Leptin and ghrelin action (firing rate)
AgRP neurons Paraventricular Hypothalamus (PVH)
ChR2 in PVH and PBN- stimulating PVH rise in food intake
AgRP inhibiting SIM-1 PVH cells
GABA antagonist
Inhibitory DREADD in SIM-1 cells
Optogenetic activation of OXT-ChR2/ SIM-1-ChR2 cells
SIM-1 Heterozygosity
Duplan 2009
Mice- Obesity and hyperphagia
Reduced AVP/OXT expressing PVH cells
Restored with ICV OXT
Cholecystikinin (CCK) reducing food intake
Infusion
Attenuated by Vagal dissection/capsaicin
Leptin reducing food intake
Leptin Receptor KO
-receptor levels decrease with feeding (produced by Ob gene)
-Vagal afferents contain STAT-3, part of the pathway which mediates leptin effects
(Buyse)
Ghrelin stimulating food intake
- cfos AgRP co-labelling after IV Ghreli
Attenuated by dissection/capsaicin
NG receptor accumulation
Insulin reducing food intake
IRS2 mRNA and KO
Depolarisation at certain concentrations
Dil from pancreas
VNS for food intake
Depressive patients
Minipigs (body weight, energy expenditure, BAT recruitment and carb consumption)
V-BLOC
Weight decrease
Affects dietary constituency
tVNS
Rats on high fat diet
Increased BAT
Increased UCP-1 B3AR expression
Arcuate nucleus/Mediobasal Hypothalamus in glucose production via PI3K
Hypothalamic insulin infusion (PI3K, K+/ATP)
Vagotomy
Insulin receptor KD/ rescue in AgRP/POMC
Dorsal Vagal complex in MAPK pathway
Western blotting (ERK1/2 phosphorylation Inhibiting ERK1/2 phosphorylation KATP channel activity Pancreatic Euglycaemic clamp (increased GIR, decrease in glucose production)
Food intake in and insulin
ICV insulin
-POMC activation (mRNA, AAV fluorescent PI3K reporter)
DVC activation (inhibition of ERK1/2)
High fat diet/ Obesity
Zucker rats: insulin sensitivity, food intake, reduced insulin effectiveness
HFD: abolished MBH and DVC responses
Overexpression of DEPTOR in the MBH
Whole body/MBH-specific O/E of DEPTOR
- Increased glucose tolerance
- Less weight gain with HFD
- Increased AKT phosphorylation
Role of Nucleus Accumbens shell (NAcSh)
O’connor
Optogenetic inhibition of Dopamine 1 r NAcSh neurons
- prolongs feeding
Activation of terminals reduces feeding
Projects to Lat Hypothalamus, inhibits GABA releasing VGAT cells
